diff mbox series

x86_64: Improvements to arithmetic right shifts of V1TImode values.

Message ID 001a01d806ee$e39c15f0$aad441d0$@nextmovesoftware.com
State New
Headers
Series x86_64: Improvements to arithmetic right shifts of V1TImode values. |

Commit Message

Roger Sayle Jan. 11, 2022, 1:26 p.m. UTC 
  This patch to the i386 backend's ix86_expand_v1ti_ashiftrt provides
improved (shorter) implementations of V1TI mode arithmetic right shifts
for constant amounts between 111 and 126 bits.  The significance of
this range is that this functionality is useful for (eventually)
providing sign extension from HImode and QImode to V1TImode.

For example, x>>112 (to sign extend a 16-bit value), was previously
generated as a four operation sequence:

        movdqa  %xmm0, %xmm1            // word    7 6 5 4 3 2 1 0
        psrad   $31, %xmm0              // V8HI = [S,S,?,?,?,?,?,?]
        psrad   $16, %xmm1              // V8HI = [S,X,?,?,?,?,?,?]
        punpckhqdq      %xmm0, %xmm1    // V8HI = [S,S,?,?,S,X,?,?]
        pshufd  $253, %xmm1, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]

with this patch, we now generates a three operation sequence:

        psrad   $16, %xmm0              // V8HI = [S,X,?,?,?,?,?,?]
        pshufhw $254, %xmm0, %xmm0      // V8HI = [S,S,S,X,?,?,?,?]
        pshufd  $254, %xmm0, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]

The correctness of generated code is confirmed by the existing
run-time test gcc.target/i386/sse2-v1ti-ashiftrt-1.c in the testsuite.
This idiom is safe to use for shifts by 127, but that case gets handled
by a two operation sequence earlier in this function.


This patch has been tested on x86_64-pc-linux-gnu with a make bootstrap
and make -k check with no new failures.  OK for mainline?


2022-01-11  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
	* config/i386/i386-expand.c (ix86_expand_v1ti_ashiftrt): Provide
	new three operation implementations for shifts by 111..126 bits.


Thanks in advance,
Roger
--

Comments

Uros Bizjak Jan. 12, 2022, 7:18 p.m. UTC | #1 
On Tue, Jan 11, 2022 at 2:26 PM Roger Sayle <roger@nextmovesoftware.com> wrote:
>
>
> This patch to the i386 backend's ix86_expand_v1ti_ashiftrt provides
> improved (shorter) implementations of V1TI mode arithmetic right shifts
> for constant amounts between 111 and 126 bits.  The significance of
> this range is that this functionality is useful for (eventually)
> providing sign extension from HImode and QImode to V1TImode.
>
> For example, x>>112 (to sign extend a 16-bit value), was previously
> generated as a four operation sequence:
>
>         movdqa  %xmm0, %xmm1            // word    7 6 5 4 3 2 1 0
>         psrad   $31, %xmm0              // V8HI = [S,S,?,?,?,?,?,?]
>         psrad   $16, %xmm1              // V8HI = [S,X,?,?,?,?,?,?]
>         punpckhqdq      %xmm0, %xmm1    // V8HI = [S,S,?,?,S,X,?,?]
>         pshufd  $253, %xmm1, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
>
> with this patch, we now generates a three operation sequence:
>
>         psrad   $16, %xmm0              // V8HI = [S,X,?,?,?,?,?,?]
>         pshufhw $254, %xmm0, %xmm0      // V8HI = [S,S,S,X,?,?,?,?]
>         pshufd  $254, %xmm0, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
>
> The correctness of generated code is confirmed by the existing
> run-time test gcc.target/i386/sse2-v1ti-ashiftrt-1.c in the testsuite.
> This idiom is safe to use for shifts by 127, but that case gets handled
> by a two operation sequence earlier in this function.
>
>
> This patch has been tested on x86_64-pc-linux-gnu with a make bootstrap
> and make -k check with no new failures.  OK for mainline?
>
>
> 2022-01-11  Roger Sayle  <roger@nextmovesoftware.com>
>
> gcc/ChangeLog
>         * config/i386/i386-expand.c (ix86_expand_v1ti_ashiftrt): Provide
>         new three operation implementations for shifts by 111..126 bits.

+  if (bits >= 111)
+    {
+      /* Three operations.  */
+      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp2 = gen_reg_rtx (V4SImode);
+      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
+      emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));

This can be written as:

rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
emit_insn (gen_ashrv4i3 (tmp2, tmp1, GEN_INT ...));

+      rtx tmp3 = gen_reg_rtx (V8HImode);
+      rtx tmp4 = gen_reg_rtx (V8HImode);
+      emit_move_insn (tmp3, gen_lowpart (V8HImode, tmp2));
+      emit_insn (gen_sse2_pshufhw (tmp4, tmp3, GEN_INT (0xfe)));

Here in a similar way...

+      rtx tmp5 = gen_reg_rtx (V4SImode);
+      rtx tmp6 = gen_reg_rtx (V4SImode);
+      emit_move_insn (tmp5, gen_lowpart (V4SImode, tmp4));
+      emit_insn (gen_sse2_pshufd (tmp6, tmp5, GEN_INT (0xfe)));

... also here.

+      rtx tmp7 = gen_reg_rtx (V1TImode);
+      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
+      emit_move_insn (operands[0], tmp7);

And here a simple:

emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6);

+      return;
+    }
+

Uros.
Roger Sayle Jan. 14, 2022, 9 a.m. UTC | #2 
Hi Uros,
Here's a revised version of this patch incorporating your suggestion of using
force_reg instead of emit_move_insn to a pseudo allocated by gen_reg_rtx.
I also took the opportunity to transition the rest of the function (and clean-up
those around it) to use this preferred idiom.

This patch has been tested on x86_64-pc-linux-gnu with a make bootstrap
and make -k check with no new failures.  OK for mainline?


2022-01-14  Roger Sayle  <roger@nextmovesoftware.com>
	    Uroš Bizjak  <ubizjak@gmail.com>

gcc/ChangeLog
	* config/i386/i386-expand.c (ix86_expand_v1ti_to_ti): Use force_reg.
	(ix86_expand_ti_to_v1ti): Use force_reg.
	(ix86_expand_v1ti_shift): Use force_reg.
	(ix86_expand_v1ti_rotate): Use force_reg.
	(ix86_expand_v1ti_ashiftrt): Provide new three operation
	implementations for shifts by 111..126 bits.  Use force_reg.


Thanks again,
Roger
--

> -----Original Message-----
> From: Uros Bizjak <ubizjak@gmail.com>
> Sent: 12 January 2022 19:18
> To: Roger Sayle <roger@nextmovesoftware.com>
> Cc: GCC Patches <gcc-patches@gcc.gnu.org>
> Subject: Re: [PATCH] x86_64: Improvements to arithmetic right shifts of
> V1TImode values.
> 
> On Tue, Jan 11, 2022 at 2:26 PM Roger Sayle <roger@nextmovesoftware.com>
> wrote:
> >
> >
> > This patch to the i386 backend's ix86_expand_v1ti_ashiftrt provides
> > improved (shorter) implementations of V1TI mode arithmetic right
> > shifts for constant amounts between 111 and 126 bits.  The
> > significance of this range is that this functionality is useful for
> > (eventually) providing sign extension from HImode and QImode to V1TImode.
> >
> > For example, x>>112 (to sign extend a 16-bit value), was previously
> > generated as a four operation sequence:
> >
> >         movdqa  %xmm0, %xmm1            // word    7 6 5 4 3 2 1 0
> >         psrad   $31, %xmm0              // V8HI = [S,S,?,?,?,?,?,?]
> >         psrad   $16, %xmm1              // V8HI = [S,X,?,?,?,?,?,?]
> >         punpckhqdq      %xmm0, %xmm1    // V8HI = [S,S,?,?,S,X,?,?]
> >         pshufd  $253, %xmm1, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
> >
> > with this patch, we now generates a three operation sequence:
> >
> >         psrad   $16, %xmm0              // V8HI = [S,X,?,?,?,?,?,?]
> >         pshufhw $254, %xmm0, %xmm0      // V8HI = [S,S,S,X,?,?,?,?]
> >         pshufd  $254, %xmm0, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
> >
> > The correctness of generated code is confirmed by the existing
> > run-time test gcc.target/i386/sse2-v1ti-ashiftrt-1.c in the testsuite.
> > This idiom is safe to use for shifts by 127, but that case gets
> > handled by a two operation sequence earlier in this function.
> >
> >
> > This patch has been tested on x86_64-pc-linux-gnu with a make
> > bootstrap and make -k check with no new failures.  OK for mainline?
> >
> >
> > 2022-01-11  Roger Sayle  <roger@nextmovesoftware.com>
> >
> > gcc/ChangeLog
> >         * config/i386/i386-expand.c (ix86_expand_v1ti_ashiftrt): Provide
> >         new three operation implementations for shifts by 111..126 bits.
> 
> +  if (bits >= 111)
> +    {
> +      /* Three operations.  */
> +      rtx tmp1 = gen_reg_rtx (V4SImode);
> +      rtx tmp2 = gen_reg_rtx (V4SImode);
> +      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
> +      emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));
> 
> This can be written as:
> 
> rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1)); emit_insn
> (gen_ashrv4i3 (tmp2, tmp1, GEN_INT ...));
> 
> +      rtx tmp3 = gen_reg_rtx (V8HImode);
> +      rtx tmp4 = gen_reg_rtx (V8HImode);
> +      emit_move_insn (tmp3, gen_lowpart (V8HImode, tmp2));
> +      emit_insn (gen_sse2_pshufhw (tmp4, tmp3, GEN_INT (0xfe)));
> 
> Here in a similar way...
> 
> +      rtx tmp5 = gen_reg_rtx (V4SImode);
> +      rtx tmp6 = gen_reg_rtx (V4SImode);
> +      emit_move_insn (tmp5, gen_lowpart (V4SImode, tmp4));
> +      emit_insn (gen_sse2_pshufd (tmp6, tmp5, GEN_INT (0xfe)));
> 
> ... also here.
> 
> +      rtx tmp7 = gen_reg_rtx (V1TImode);
> +      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
> +      emit_move_insn (operands[0], tmp7);
> 
> And here a simple:
> 
> emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6);
> 
> +      return;
> +    }
> +
> 
> Uros.
diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 0318f12..c740d6e 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -6211,8 +6211,7 @@ ix86_expand_v1ti_to_ti (rtx x)
   rtx result = gen_reg_rtx (TImode);
   if (TARGET_SSE2)
     {
-      rtx temp = gen_reg_rtx (V2DImode);
-      emit_move_insn (temp, gen_lowpart (V2DImode, x));
+      rtx temp = force_reg (V2DImode, gen_lowpart (V2DImode, x));
       rtx lo = gen_lowpart (DImode, result);
       emit_insn (gen_vec_extractv2didi (lo, temp, const0_rtx));
       rtx hi = gen_highpart (DImode, result);
@@ -6227,18 +6226,16 @@ ix86_expand_v1ti_to_ti (rtx x)
 static rtx
 ix86_expand_ti_to_v1ti (rtx x)
 {
-  rtx result = gen_reg_rtx (V1TImode);
   if (TARGET_SSE2)
     {
       rtx lo = gen_lowpart (DImode, x);
       rtx hi = gen_highpart (DImode, x);
       rtx tmp = gen_reg_rtx (V2DImode);
       emit_insn (gen_vec_concatv2di (tmp, lo, hi));
-      emit_move_insn (result, gen_lowpart (V1TImode, tmp));
+      return force_reg (V1TImode, gen_lowpart (V1TImode, tmp));
     }
-  else
-    emit_move_insn (result, gen_lowpart (V1TImode, x));
-  return result;
+
+  return force_reg (V1TImode, gen_lowpart (V1TImode, x));
 }
 
 /* Expand V1TI mode shift (of rtx_code CODE) by constant.  */
@@ -6285,8 +6282,7 @@ ix86_expand_v1ti_shift (enum rtx_code code, rtx operands[])
     emit_insn (gen_sse2_lshrv1ti3 (tmp1, op1, GEN_INT (64)));
 
   /* tmp2 is operands[1] shifted by 64, in V2DImode.  */
-  rtx tmp2 = gen_reg_rtx (V2DImode);
-  emit_move_insn (tmp2, gen_lowpart (V2DImode, tmp1));
+  rtx tmp2 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp1));
 
   /* tmp3 will be the V2DImode result.  */
   rtx tmp3 = gen_reg_rtx (V2DImode);
@@ -6301,8 +6297,7 @@ ix86_expand_v1ti_shift (enum rtx_code code, rtx operands[])
   else
     {
       /* tmp4 is operands[1], in V2DImode.  */
-      rtx tmp4 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, op1));
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, op1));
 
       rtx tmp5 = gen_reg_rtx (V2DImode);
       if (code == ASHIFT)
@@ -6320,8 +6315,7 @@ ix86_expand_v1ti_shift (enum rtx_code code, rtx operands[])
     }
 
   /* Convert the result back to V1TImode and store in operands[0].  */
-  rtx tmp7 = gen_reg_rtx (V1TImode);
-  emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp3));
+  rtx tmp7 = force_reg (V1TImode, gen_lowpart (V1TImode, tmp3));
   emit_move_insn (operands[0], tmp7);
 }
 
@@ -6356,19 +6350,15 @@ ix86_expand_v1ti_rotate (enum rtx_code code, rtx operands[])
 
   if ((bits & 31) == 0)
     {
-      rtx tmp1 = gen_reg_rtx (V4SImode);
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      rtx tmp3 = gen_reg_rtx (V1TImode);
-
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       if (bits == 32)
 	emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0x93)));
       else if (bits == 64)
 	emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0x4e)));
       else
 	emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0x39)));
-      emit_move_insn (tmp3, gen_lowpart (V1TImode, tmp2));
-      emit_move_insn (operands[0], tmp3);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp2));
       return;
     }
 
@@ -6385,8 +6375,7 @@ ix86_expand_v1ti_rotate (enum rtx_code code, rtx operands[])
       return;
     }
 
-  rtx op1_v4si = gen_reg_rtx (V4SImode);
-  emit_move_insn (op1_v4si, gen_lowpart (V4SImode, op1));
+  rtx op1_v4si = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
 
   rtx lobits;
   rtx hibits;
@@ -6423,13 +6412,12 @@ ix86_expand_v1ti_rotate (enum rtx_code code, rtx operands[])
   rtx tmp1 = gen_reg_rtx (V4SImode);
   rtx tmp2 = gen_reg_rtx (V4SImode);
   rtx tmp3 = gen_reg_rtx (V4SImode);
-  rtx tmp4 = gen_reg_rtx (V1TImode);
 
   emit_insn (gen_ashlv4si3 (tmp1, lobits, GEN_INT (bits & 31)));
   emit_insn (gen_lshrv4si3 (tmp2, hibits, GEN_INT (32 - (bits & 31))));
   emit_insn (gen_iorv4si3 (tmp3, tmp1, tmp2));
-  emit_move_insn (tmp4, gen_lowpart (V1TImode, tmp3));
-  emit_move_insn (operands[0], tmp4);
+
+  emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp3));
 }
 
 /* Expand V1TI mode ashiftrt by constant.  */
@@ -6459,67 +6447,72 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
   if (bits == 127)
     {
       /* Two operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg(V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
       emit_insn (gen_ashrv4si3 (tmp3, tmp2, GEN_INT (31)));
 
-      rtx tmp4 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp4, gen_lowpart (V1TImode, tmp3));
-      emit_move_insn (operands[0], tmp4);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp3));
       return;
     }
 
   if (bits == 64)
     {
       /* Three operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg(V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
       emit_insn (gen_ashrv4si3 (tmp3, tmp2, GEN_INT (31)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
-      rtx tmp5 = gen_reg_rtx (V2DImode);
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp1));
+      rtx tmp5 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp3));
       rtx tmp6 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, tmp1));
-      emit_move_insn (tmp5, gen_lowpart (V2DImode, tmp3));
       emit_insn (gen_vec_interleave_highv2di (tmp6, tmp4, tmp5));
 
-      rtx tmp7 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
-      emit_move_insn (operands[0], tmp7);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6));
       return;
     }
 
   if (bits == 96)
     {
       /* Three operations.  */
-      rtx tmp3 = gen_reg_rtx (V2DImode);
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg(V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (31)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
+      rtx tmp3 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp1));
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp2));
       rtx tmp5 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp3, gen_lowpart (V2DImode, tmp1));
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, tmp2));
       emit_insn (gen_vec_interleave_highv2di (tmp5, tmp3, tmp4));
 
-      rtx tmp6 = gen_reg_rtx (V4SImode);
+      rtx tmp6 = force_reg(V4SImode, gen_lowpart (V4SImode, tmp5));
       rtx tmp7 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp6, gen_lowpart (V4SImode, tmp5));
       emit_insn (gen_sse2_pshufd (tmp7, tmp6, GEN_INT (0xfd)));
 
-      rtx tmp8 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp8, gen_lowpart (V1TImode, tmp7));
-      emit_move_insn (operands[0], tmp8);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp7));
+      return;
+    }
+
+  if (bits >= 111)
+    {
+      /* Three operations.  */
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
+      rtx tmp2 = gen_reg_rtx (V4SImode);
+      emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));
+
+      rtx tmp3 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp2));
+      rtx tmp4 = gen_reg_rtx (V8HImode);
+      emit_insn (gen_sse2_pshufhw (tmp4, tmp3, GEN_INT (0xfe)));
+
+      rtx tmp5 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp4));
+      rtx tmp6 = gen_reg_rtx (V4SImode);
+      emit_insn (gen_sse2_pshufd (tmp6, tmp5, GEN_INT (0xfe)));
+
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6));
       return;
     }
 
@@ -6528,9 +6521,8 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       /* Three operations.  */
       if (bits == 32)
 	{
-	  rtx tmp1 = gen_reg_rtx (V4SImode);
+	  rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
 	  rtx tmp2 = gen_reg_rtx (V4SImode);
-	  emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
 	  emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (31)));
 
 	  rtx tmp3 = gen_reg_rtx (V1TImode);
@@ -6538,29 +6530,22 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
 
 	  if (TARGET_AVX2)
 	    {
-	      rtx tmp4 = gen_reg_rtx (V4SImode);
+	      rtx tmp4 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp3));
 	      rtx tmp5 = gen_reg_rtx (V4SImode);
-	      emit_move_insn (tmp4, gen_lowpart (V4SImode, tmp3));
 	      emit_insn (gen_avx2_pblenddv4si (tmp5, tmp2, tmp4,
 					       GEN_INT (7)));
 
-	      rtx tmp6 = gen_reg_rtx (V1TImode);
-	      emit_move_insn (tmp6, gen_lowpart (V1TImode, tmp5));
-	      emit_move_insn (operands[0], tmp6);
+	      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp5));
 	    }
 	  else
 	    {
-	      rtx tmp4 = gen_reg_rtx (V8HImode);
-	      rtx tmp5 = gen_reg_rtx (V8HImode);
+	      rtx tmp4 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp2));
+	      rtx tmp5 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp3));
 	      rtx tmp6 = gen_reg_rtx (V8HImode);
-	      emit_move_insn (tmp4, gen_lowpart (V8HImode, tmp2));
-	      emit_move_insn (tmp5, gen_lowpart (V8HImode, tmp3));
 	      emit_insn (gen_sse4_1_pblendw (tmp6, tmp4, tmp5,
 					     GEN_INT (0x3f)));
 
-	      rtx tmp7 = gen_reg_rtx (V1TImode);
-	      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
-	      emit_move_insn (operands[0], tmp7);
+	      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6));
 	    }
 	  return;
 	}
@@ -6568,9 +6553,8 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       /* Three operations.  */
       if (bits == 8 || bits == 16 || bits == 24)
 	{
-	  rtx tmp1 = gen_reg_rtx (V4SImode);
+	  rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
 	  rtx tmp2 = gen_reg_rtx (V4SImode);
-	  emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
 	  emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits)));
 
 	  rtx tmp3 = gen_reg_rtx (V1TImode);
@@ -6578,29 +6562,22 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
 
 	  if (TARGET_AVX2)
 	    {
-	      rtx tmp4 = gen_reg_rtx (V4SImode);
+	      rtx tmp4 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp3));
 	      rtx tmp5 = gen_reg_rtx (V4SImode);
-	      emit_move_insn (tmp4, gen_lowpart (V4SImode, tmp3));
 	      emit_insn (gen_avx2_pblenddv4si (tmp5, tmp2, tmp4,
 					       GEN_INT (7)));
 
-	      rtx tmp6 = gen_reg_rtx (V1TImode);
-	      emit_move_insn (tmp6, gen_lowpart (V1TImode, tmp5));
-	      emit_move_insn (operands[0], tmp6);
+	      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp5));
 	    }
 	  else
 	    {
-	      rtx tmp4 = gen_reg_rtx (V8HImode);
-	      rtx tmp5 = gen_reg_rtx (V8HImode);
+	      rtx tmp4 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp2));
+	      rtx tmp5 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp3));
 	      rtx tmp6 = gen_reg_rtx (V8HImode);
-	      emit_move_insn (tmp4, gen_lowpart (V8HImode, tmp2));
-	      emit_move_insn (tmp5, gen_lowpart (V8HImode, tmp3));
 	      emit_insn (gen_sse4_1_pblendw (tmp6, tmp4, tmp5,
 					     GEN_INT (0x3f)));
 
-	      rtx tmp7 = gen_reg_rtx (V1TImode);
-	      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
-	      emit_move_insn (operands[0], tmp7);
+	      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6));
 	    }
 	  return;
 	}
@@ -6609,38 +6586,31 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
   if (bits > 96)
     {
       /* Four operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
       emit_insn (gen_ashrv4si3 (tmp3, tmp1, GEN_INT (31)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
-      rtx tmp5 = gen_reg_rtx (V2DImode);
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp2));
+      rtx tmp5 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp3));
       rtx tmp6 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, tmp2));
-      emit_move_insn (tmp5, gen_lowpart (V2DImode, tmp3));
       emit_insn (gen_vec_interleave_highv2di (tmp6, tmp4, tmp5));
 
-      rtx tmp7 = gen_reg_rtx (V4SImode);
+      rtx tmp7 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp6));
       rtx tmp8 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp7, gen_lowpart (V4SImode, tmp6));
       emit_insn (gen_sse2_pshufd (tmp8, tmp7, GEN_INT (0xfd)));
 
-      rtx tmp9 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp9, gen_lowpart (V1TImode, tmp8));
-      emit_move_insn (operands[0], tmp9);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp8));
       return;
     }
 
   if (TARGET_SSE4_1 && (bits == 48 || bits == 80))
     {
       /* Four operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
@@ -6649,26 +6619,21 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp4 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp4, op1, GEN_INT (bits)));
 
-      rtx tmp5 = gen_reg_rtx (V8HImode);
-      rtx tmp6 = gen_reg_rtx (V8HImode);
+      rtx tmp5 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp3));
+      rtx tmp6 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp4));
       rtx tmp7 = gen_reg_rtx (V8HImode);
-      emit_move_insn (tmp5, gen_lowpart (V8HImode, tmp3));
-      emit_move_insn (tmp6, gen_lowpart (V8HImode, tmp4));
       emit_insn (gen_sse4_1_pblendw (tmp7, tmp5, tmp6,
 				     GEN_INT (bits == 48 ? 0x1f : 0x07)));
 
-      rtx tmp8 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp8, gen_lowpart (V1TImode, tmp7));
-      emit_move_insn (operands[0], tmp8);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp7));
       return;
     }
 
   if ((bits & 7) == 0)
     {
       /* Five operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
@@ -6677,93 +6642,75 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp4 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp4, op1, GEN_INT (bits)));
 
-      rtx tmp5 = gen_reg_rtx (V1TImode);
+      rtx tmp5 = force_reg (V1TImode, gen_lowpart (V1TImode, tmp3));
       rtx tmp6 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp5, gen_lowpart (V1TImode, tmp3));
       emit_insn (gen_sse2_ashlv1ti3 (tmp6, tmp5, GEN_INT (128 - bits)));
 
-      rtx tmp7 = gen_reg_rtx (V2DImode);
-      rtx tmp8 = gen_reg_rtx (V2DImode);
+      rtx tmp7 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp4));
+      rtx tmp8 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp6));
       rtx tmp9 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp7, gen_lowpart (V2DImode, tmp4));
-      emit_move_insn (tmp8, gen_lowpart (V2DImode, tmp6));
       emit_insn (gen_iorv2di3 (tmp9, tmp7, tmp8));
 
-      rtx tmp10 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp10, gen_lowpart (V1TImode, tmp9));
-      emit_move_insn (operands[0], tmp10);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp9));
       return;
     }
 
   if (TARGET_AVX2 && bits < 32)
     {
       /* Six operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits)));
 
       rtx tmp3 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp3, op1, GEN_INT (64)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, op1));
       rtx tmp5 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, op1));
       emit_insn (gen_lshrv2di3 (tmp5, tmp4, GEN_INT (bits)));
 
-      rtx tmp6 = gen_reg_rtx (V2DImode);
+      rtx tmp6 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp3));
       rtx tmp7 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp6, gen_lowpart (V2DImode, tmp3));
       emit_insn (gen_ashlv2di3 (tmp7, tmp6, GEN_INT (64 - bits)));
 
       rtx tmp8 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp8, tmp5, tmp7));
 
-      rtx tmp9 = gen_reg_rtx (V4SImode);
+      rtx tmp9 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp8));
       rtx tmp10 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp9, gen_lowpart (V4SImode, tmp8));
       emit_insn (gen_avx2_pblenddv4si (tmp10, tmp2, tmp9, GEN_INT (7)));
 
-      rtx tmp11 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp11, gen_lowpart (V1TImode, tmp10));
-      emit_move_insn (operands[0], tmp11);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp10));
       return;
     }
 
   if (TARGET_SSE4_1 && bits < 15)
     {
       /* Six operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits)));
 
       rtx tmp3 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp3, op1, GEN_INT (64)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, op1));
       rtx tmp5 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, op1));
       emit_insn (gen_lshrv2di3 (tmp5, tmp4, GEN_INT (bits)));
 
-      rtx tmp6 = gen_reg_rtx (V2DImode);
+      rtx tmp6 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp3));
       rtx tmp7 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp6, gen_lowpart (V2DImode, tmp3));
       emit_insn (gen_ashlv2di3 (tmp7, tmp6, GEN_INT (64 - bits)));
 
       rtx tmp8 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp8, tmp5, tmp7));
 
-      rtx tmp9 = gen_reg_rtx (V8HImode);
-      rtx tmp10 = gen_reg_rtx (V8HImode);
+      rtx tmp9 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp2));
+      rtx tmp10 = force_reg (V8HImode, gen_lowpart (V8HImode, tmp8));
       rtx tmp11 = gen_reg_rtx (V8HImode);
-      emit_move_insn (tmp9, gen_lowpart (V8HImode, tmp2));
-      emit_move_insn (tmp10, gen_lowpart (V8HImode, tmp8));
       emit_insn (gen_sse4_1_pblendw (tmp11, tmp9, tmp10, GEN_INT (0x3f)));
 
-      rtx tmp12 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp12, gen_lowpart (V1TImode, tmp11));
-      emit_move_insn (operands[0], tmp12);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp11));
       return;
     }
 
@@ -6773,14 +6720,12 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp1 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp1, op1, GEN_INT (64)));
 
-      rtx tmp2 = gen_reg_rtx (V2DImode);
+      rtx tmp2 = force_reg (V2DImode, gen_lowpart (V2DImode, op1));
       rtx tmp3 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp2, gen_lowpart (V2DImode, op1));
       emit_insn (gen_lshrv2di3 (tmp3, tmp2, GEN_INT (1)));
 
-      rtx tmp4 = gen_reg_rtx (V2DImode);
+      rtx tmp4 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp1));
       rtx tmp5 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp4, gen_lowpart (V2DImode, tmp1));
       emit_insn (gen_ashlv2di3 (tmp5, tmp4, GEN_INT (63)));
 
       rtx tmp6 = gen_reg_rtx (V2DImode);
@@ -6789,31 +6734,26 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp7 = gen_reg_rtx (V2DImode);
       emit_insn (gen_lshrv2di3 (tmp7, tmp2, GEN_INT (63)));
 
-      rtx tmp8 = gen_reg_rtx (V4SImode);
+      rtx tmp8 = force_reg (V4SImode, gen_lowpart (V4SImode, tmp7));
       rtx tmp9 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp8, gen_lowpart (V4SImode, tmp7));
       emit_insn (gen_sse2_pshufd (tmp9, tmp8, GEN_INT (0xbf)));
 
-      rtx tmp10 = gen_reg_rtx (V2DImode);
+      rtx tmp10 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp9));
       rtx tmp11 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp10, gen_lowpart (V2DImode, tmp9));
       emit_insn (gen_ashlv2di3 (tmp11, tmp10, GEN_INT (31)));
 
       rtx tmp12 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp12, tmp6, tmp11));
 
-      rtx tmp13 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp13, gen_lowpart (V1TImode, tmp12));
-      emit_move_insn (operands[0], tmp13);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp12));
       return;
     }
 
   if (bits > 64)
     {
       /* Eight operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
@@ -6822,39 +6762,32 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp4 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp4, op1, GEN_INT (64)));
 
-      rtx tmp5 = gen_reg_rtx (V2DImode);
+      rtx tmp5 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp4));
       rtx tmp6 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp5, gen_lowpart (V2DImode, tmp4));
       emit_insn (gen_lshrv2di3 (tmp6, tmp5, GEN_INT (bits - 64)));
 
-      rtx tmp7 = gen_reg_rtx (V1TImode);
+      rtx tmp7 = force_reg (V1TImode, gen_lowpart (V1TImode, tmp3));
       rtx tmp8 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp3));
       emit_insn (gen_sse2_ashlv1ti3 (tmp8, tmp7, GEN_INT (64)));
  
-      rtx tmp9 = gen_reg_rtx (V2DImode);
+      rtx tmp9 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp3));
       rtx tmp10 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp9, gen_lowpart (V2DImode, tmp3));
       emit_insn (gen_ashlv2di3 (tmp10, tmp9, GEN_INT (128 - bits)));
 
-      rtx tmp11 = gen_reg_rtx (V2DImode);
+      rtx tmp11 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp8));
       rtx tmp12 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp11, gen_lowpart (V2DImode, tmp8));
       emit_insn (gen_iorv2di3 (tmp12, tmp10, tmp11));
 
       rtx tmp13 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp13, tmp6, tmp12));
 
-      rtx tmp14 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp14, gen_lowpart (V1TImode, tmp13));
-      emit_move_insn (operands[0], tmp14);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp13));
     }
   else
     {
       /* Nine operations.  */
-      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1));
       rtx tmp2 = gen_reg_rtx (V4SImode);
-      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_sse2_pshufd (tmp2, tmp1, GEN_INT (0xff)));
 
       rtx tmp3 = gen_reg_rtx (V4SImode);
@@ -6863,35 +6796,29 @@ ix86_expand_v1ti_ashiftrt (rtx operands[])
       rtx tmp4 = gen_reg_rtx (V1TImode);
       emit_insn (gen_sse2_lshrv1ti3 (tmp4, op1, GEN_INT (64)));
 
-      rtx tmp5 = gen_reg_rtx (V2DImode);
+      rtx tmp5 = force_reg (V2DImode, gen_lowpart (V2DImode, op1));
       rtx tmp6 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp5, gen_lowpart (V2DImode, op1));
       emit_insn (gen_lshrv2di3 (tmp6, tmp5, GEN_INT (bits)));
 
-      rtx tmp7 = gen_reg_rtx (V2DImode);
+      rtx tmp7 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp4));
       rtx tmp8 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp7, gen_lowpart (V2DImode, tmp4));
       emit_insn (gen_ashlv2di3 (tmp8, tmp7, GEN_INT (64 - bits)));
 
       rtx tmp9 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp9, tmp6, tmp8));
 
-      rtx tmp10 = gen_reg_rtx (V1TImode);
+      rtx tmp10 = force_reg (V1TImode, gen_lowpart (V1TImode, tmp3));
       rtx tmp11 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp10, gen_lowpart (V1TImode, tmp3));
       emit_insn (gen_sse2_ashlv1ti3 (tmp11, tmp10, GEN_INT (64)));
 
-      rtx tmp12 = gen_reg_rtx (V2DImode);
+      rtx tmp12 = force_reg (V2DImode, gen_lowpart (V2DImode, tmp11));
       rtx tmp13 = gen_reg_rtx (V2DImode);
-      emit_move_insn (tmp12, gen_lowpart (V2DImode, tmp11));
       emit_insn (gen_ashlv2di3 (tmp13, tmp12, GEN_INT (64 - bits)));
 
       rtx tmp14 = gen_reg_rtx (V2DImode);
       emit_insn (gen_iorv2di3 (tmp14, tmp9, tmp13));
 
-      rtx tmp15 = gen_reg_rtx (V1TImode);
-      emit_move_insn (tmp15, gen_lowpart (V1TImode, tmp14));
-      emit_move_insn (operands[0], tmp15);
+      emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp14));
     }
 }
Uros Bizjak Jan. 14, 2022, 9:22 a.m. UTC | #3 
On Fri, Jan 14, 2022 at 10:00 AM Roger Sayle <roger@nextmovesoftware.com> wrote:
>
>
> Hi Uros,
> Here's a revised version of this patch incorporating your suggestion of using
> force_reg instead of emit_move_insn to a pseudo allocated by gen_reg_rtx.
> I also took the opportunity to transition the rest of the function (and clean-up
> those around it) to use this preferred idiom.
>
> This patch has been tested on x86_64-pc-linux-gnu with a make bootstrap
> and make -k check with no new failures.  OK for mainline?
>
>
> 2022-01-14  Roger Sayle  <roger@nextmovesoftware.com>
>             Uroš Bizjak  <ubizjak@gmail.com>
>
> gcc/ChangeLog
>         * config/i386/i386-expand.c (ix86_expand_v1ti_to_ti): Use force_reg.
>         (ix86_expand_ti_to_v1ti): Use force_reg.
>         (ix86_expand_v1ti_shift): Use force_reg.
>         (ix86_expand_v1ti_rotate): Use force_reg.
>         (ix86_expand_v1ti_ashiftrt): Provide new three operation
>         implementations for shifts by 111..126 bits.  Use force_reg.

LGTM, as far as I can review the patch due to code churn...

Thanks,
Uros.

>
> Thanks again,
> Roger
> --
>
> > -----Original Message-----
> > From: Uros Bizjak <ubizjak@gmail.com>
> > Sent: 12 January 2022 19:18
> > To: Roger Sayle <roger@nextmovesoftware.com>
> > Cc: GCC Patches <gcc-patches@gcc.gnu.org>
> > Subject: Re: [PATCH] x86_64: Improvements to arithmetic right shifts of
> > V1TImode values.
> >
> > On Tue, Jan 11, 2022 at 2:26 PM Roger Sayle <roger@nextmovesoftware.com>
> > wrote:
> > >
> > >
> > > This patch to the i386 backend's ix86_expand_v1ti_ashiftrt provides
> > > improved (shorter) implementations of V1TI mode arithmetic right
> > > shifts for constant amounts between 111 and 126 bits.  The
> > > significance of this range is that this functionality is useful for
> > > (eventually) providing sign extension from HImode and QImode to V1TImode.
> > >
> > > For example, x>>112 (to sign extend a 16-bit value), was previously
> > > generated as a four operation sequence:
> > >
> > >         movdqa  %xmm0, %xmm1            // word    7 6 5 4 3 2 1 0
> > >         psrad   $31, %xmm0              // V8HI = [S,S,?,?,?,?,?,?]
> > >         psrad   $16, %xmm1              // V8HI = [S,X,?,?,?,?,?,?]
> > >         punpckhqdq      %xmm0, %xmm1    // V8HI = [S,S,?,?,S,X,?,?]
> > >         pshufd  $253, %xmm1, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
> > >
> > > with this patch, we now generates a three operation sequence:
> > >
> > >         psrad   $16, %xmm0              // V8HI = [S,X,?,?,?,?,?,?]
> > >         pshufhw $254, %xmm0, %xmm0      // V8HI = [S,S,S,X,?,?,?,?]
> > >         pshufd  $254, %xmm0, %xmm0      // V8HI = [S,S,S,S,S,S,S,X]
> > >
> > > The correctness of generated code is confirmed by the existing
> > > run-time test gcc.target/i386/sse2-v1ti-ashiftrt-1.c in the testsuite.
> > > This idiom is safe to use for shifts by 127, but that case gets
> > > handled by a two operation sequence earlier in this function.
> > >
> > >
> > > This patch has been tested on x86_64-pc-linux-gnu with a make
> > > bootstrap and make -k check with no new failures.  OK for mainline?
> > >
> > >
> > > 2022-01-11  Roger Sayle  <roger@nextmovesoftware.com>
> > >
> > > gcc/ChangeLog
> > >         * config/i386/i386-expand.c (ix86_expand_v1ti_ashiftrt): Provide
> > >         new three operation implementations for shifts by 111..126 bits.
> >
> > +  if (bits >= 111)
> > +    {
> > +      /* Three operations.  */
> > +      rtx tmp1 = gen_reg_rtx (V4SImode);
> > +      rtx tmp2 = gen_reg_rtx (V4SImode);
> > +      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
> > +      emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));
> >
> > This can be written as:
> >
> > rtx tmp1 = force_reg (V4SImode, gen_lowpart (V4SImode, op1)); emit_insn
> > (gen_ashrv4i3 (tmp2, tmp1, GEN_INT ...));
> >
> > +      rtx tmp3 = gen_reg_rtx (V8HImode);
> > +      rtx tmp4 = gen_reg_rtx (V8HImode);
> > +      emit_move_insn (tmp3, gen_lowpart (V8HImode, tmp2));
> > +      emit_insn (gen_sse2_pshufhw (tmp4, tmp3, GEN_INT (0xfe)));
> >
> > Here in a similar way...
> >
> > +      rtx tmp5 = gen_reg_rtx (V4SImode);
> > +      rtx tmp6 = gen_reg_rtx (V4SImode);
> > +      emit_move_insn (tmp5, gen_lowpart (V4SImode, tmp4));
> > +      emit_insn (gen_sse2_pshufd (tmp6, tmp5, GEN_INT (0xfe)));
> >
> > ... also here.
> >
> > +      rtx tmp7 = gen_reg_rtx (V1TImode);
> > +      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
> > +      emit_move_insn (operands[0], tmp7);
> >
> > And here a simple:
> >
> > emit_move_insn (operands[0], gen_lowpart (V1TImode, tmp6);
> >
> > +      return;
> > +    }
> > +
> >
> > Uros.
diff mbox series

Patch

diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 95bba25..3138b5f 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -6470,12 +6470,12 @@  ix86_expand_v1ti_ashiftrt (rtx operands[])
   if (bits == 96)
     {
       /* Three operations.  */
-      rtx tmp3 = gen_reg_rtx (V2DImode);
       rtx tmp1 = gen_reg_rtx (V4SImode);
       rtx tmp2 = gen_reg_rtx (V4SImode);
       emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
       emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (31)));
 
+      rtx tmp3 = gen_reg_rtx (V2DImode);
       rtx tmp4 = gen_reg_rtx (V2DImode);
       rtx tmp5 = gen_reg_rtx (V2DImode);
       emit_move_insn (tmp3, gen_lowpart (V2DImode, tmp1));
@@ -6493,6 +6493,30 @@  ix86_expand_v1ti_ashiftrt (rtx operands[])
       return;
     }
 
+  if (bits >= 111)
+    {
+      /* Three operations.  */
+      rtx tmp1 = gen_reg_rtx (V4SImode);
+      rtx tmp2 = gen_reg_rtx (V4SImode);
+      emit_move_insn (tmp1, gen_lowpart (V4SImode, op1));
+      emit_insn (gen_ashrv4si3 (tmp2, tmp1, GEN_INT (bits - 96)));
+
+      rtx tmp3 = gen_reg_rtx (V8HImode);
+      rtx tmp4 = gen_reg_rtx (V8HImode);
+      emit_move_insn (tmp3, gen_lowpart (V8HImode, tmp2));
+      emit_insn (gen_sse2_pshufhw (tmp4, tmp3, GEN_INT (0xfe)));
+
+      rtx tmp5 = gen_reg_rtx (V4SImode);
+      rtx tmp6 = gen_reg_rtx (V4SImode);
+      emit_move_insn (tmp5, gen_lowpart (V4SImode, tmp4));
+      emit_insn (gen_sse2_pshufd (tmp6, tmp5, GEN_INT (0xfe)));
+
+      rtx tmp7 = gen_reg_rtx (V1TImode);
+      emit_move_insn (tmp7, gen_lowpart (V1TImode, tmp6));
+      emit_move_insn (operands[0], tmp7);
+      return;
+    }
+
   if (TARGET_AVX2 || TARGET_SSE4_1)
     {
       /* Three operations.  */