diff mbox series

[v3] RISC-V: Introduce -mvector-strict-align.

Message ID aadc64da-0b0a-4035-89a8-660010da58bd@gmail.com
State Superseded
Headers
Series [v3] RISC-V: Introduce -mvector-strict-align. |

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Commit Message

Robin Dapp May 27, 2024, 12:45 p.m. UTC 
  Attached is v3 with the discussed changes.  It now has
-mscalar-strict-align which is an alias to -mstrict-align as well
as -mvector-strict-align.

Testsuite shows no new regressions on rv64gcv_zvfh_zvbb.

Regards
 Robin

gcc/ChangeLog:

	* config/riscv/riscv-opts.h (TARGET_VECTOR_MISALIGN_SUPPORTED):
	Move from here...
	* config/riscv/riscv.h (TARGET_VECTOR_MISALIGN_SUPPORTED):
	...to here and map to riscv_vector_unaligned_access_p.
	* config/riscv/riscv.opt: Add -mvector-strict-align.
	* config/riscv/riscv.cc (struct riscv_tune_param): Add
	vector_unaligned_access.
	(riscv_override_options_internal): Set
	riscv_vector_unaligned_access_p.
	* doc/invoke.texi: Document -mvector-strict-align.

gcc/testsuite/ChangeLog:

	* lib/target-supports.exp: Add
	check_effective_target_riscv_v_misalign_ok.
	* gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c: Add
	-mno-vector-strict-align.
	* gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-10.c: Ditto.
	* gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-11.c: Ditto.
	* gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-12.c: Ditto.
	* gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-8.c: Ditto.
	* gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-9.c: Ditto.
	* gcc.target/riscv/rvv/autovec/vls/misalign-1.c: Ditto.
---
 gcc/config/riscv/riscv-opts.h                 |  3 --
 gcc/config/riscv/riscv.cc                     | 19 +++++++++++
 gcc/config/riscv/riscv.h                      |  5 +++
 gcc/config/riscv/riscv.opt                    |  8 +++++
 gcc/doc/invoke.texi                           | 22 ++++++++++++
 .../costmodel/riscv/rvv/dynamic-lmul2-7.c     |  2 +-
 .../vect/costmodel/riscv/rvv/vla_vs_vls-10.c  |  2 +-
 .../vect/costmodel/riscv/rvv/vla_vs_vls-11.c  |  2 +-
 .../vect/costmodel/riscv/rvv/vla_vs_vls-12.c  |  2 +-
 .../vect/costmodel/riscv/rvv/vla_vs_vls-8.c   |  2 +-
 .../vect/costmodel/riscv/rvv/vla_vs_vls-9.c   |  2 +-
 .../riscv/rvv/autovec/vls/misalign-1.c        |  2 +-
 gcc/testsuite/lib/target-supports.exp         | 34 +++++++++++++++++--
 13 files changed, 93 insertions(+), 12 deletions(-)

Comments

Kito Cheng May 27, 2024, 2:05 p.m. UTC | #1 
> @@ -9536,6 +9549,12 @@ riscv_override_options_internal (struct gcc_options *opts)
>    riscv_slow_unaligned_access_p = (cpu->tune_param->slow_unaligned_access
>                                    || TARGET_STRICT_ALIGN);
>
> +  /* By default, when -mno-vector-strict-align is not specified, do not allow
> +     unaligned vector memory accesses except if -mtune's setting explicitly
> +     allows it.  */
> +  riscv_vector_unaligned_access_p = rvv_vector_strict_align == 0 ||

opts->x_rvv_vector_strict_align rather than rvv_vector_strict_align,
rvv_vector_strict_align is alias of global_options.x_rvv_vector_strict_align

> +    cpu->tune_param->vector_unaligned_access;
> +
>    /* Make a note if user explicitly passed -mstrict-align for later
>       builtin macro generation.  Can't use target_flags_explicitly since
>       it is set even for -mno-strict-align.  */
Robin Dapp May 27, 2024, 2:13 p.m. UTC | #2 
>> +  /* By default, when -mno-vector-strict-align is not specified, do not allow
>> +     unaligned vector memory accesses except if -mtune's setting explicitly
>> +     allows it.  */
>> +  riscv_vector_unaligned_access_p = rvv_vector_strict_align == 0 ||
> 
> opts->x_rvv_vector_strict_align rather than rvv_vector_strict_align,
> rvv_vector_strict_align is alias of global_options.x_rvv_vector_strict_align

Ah, yes, good catch.  And the line break after || was also wrong.
Corrected it locally and will wait for further comments.

Regards
 Robin
diff mbox series

Patch

diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
index 1b2dd5757a8..f58a07abffc 100644
--- a/gcc/config/riscv/riscv-opts.h
+++ b/gcc/config/riscv/riscv-opts.h
@@ -147,9 +147,6 @@  enum rvv_vector_bits_enum {
      ? 0                                                                       \
      : 32 << (__builtin_popcount (opts->x_riscv_zvl_flags) - 1))
 
-/* TODO: Enable RVV movmisalign by default for now.  */
-#define TARGET_VECTOR_MISALIGN_SUPPORTED 1
-
 /* The maximmum LMUL according to user configuration.  */
 #define TARGET_MAX_LMUL                                                        \
   (int) (rvv_max_lmul == RVV_DYNAMIC ? RVV_M8 : rvv_max_lmul)
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 85df5b7ab49..7482f51b8dc 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -287,6 +287,7 @@  struct riscv_tune_param
   unsigned short memory_cost;
   unsigned short fmv_cost;
   bool slow_unaligned_access;
+  bool vector_unaligned_access;
   bool use_divmod_expansion;
   bool overlap_op_by_pieces;
   unsigned int fusible_ops;
@@ -299,6 +300,10 @@  struct riscv_tune_param
 /* Whether unaligned accesses execute very slowly.  */
 bool riscv_slow_unaligned_access_p;
 
+/* Whether misaligned vector accesses are supported (i.e. do not
+   throw an exception).  */
+bool riscv_vector_unaligned_access_p;
+
 /* Whether user explicitly passed -mstrict-align.  */
 bool riscv_user_wants_strict_align;
 
@@ -441,6 +446,7 @@  static const struct riscv_tune_param rocket_tune_info = {
   5,						/* memory_cost */
   8,						/* fmv_cost */
   true,						/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_NOTHING,                           /* fusible_ops */
@@ -459,6 +465,7 @@  static const struct riscv_tune_param sifive_7_tune_info = {
   3,						/* memory_cost */
   8,						/* fmv_cost */
   true,						/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_NOTHING,                           /* fusible_ops */
@@ -477,6 +484,7 @@  static const struct riscv_tune_param sifive_p400_tune_info = {
   3,						/* memory_cost */
   4,						/* fmv_cost */
   true,						/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_LUI_ADDI | RISCV_FUSE_AUIPC_ADDI,  /* fusible_ops */
@@ -495,6 +503,7 @@  static const struct riscv_tune_param sifive_p600_tune_info = {
   3,						/* memory_cost */
   4,						/* fmv_cost */
   true,						/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_LUI_ADDI | RISCV_FUSE_AUIPC_ADDI,  /* fusible_ops */
@@ -513,6 +522,7 @@  static const struct riscv_tune_param thead_c906_tune_info = {
   5,            /* memory_cost */
   8,		/* fmv_cost */
   false,            /* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,	/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_NOTHING,                           /* fusible_ops */
@@ -531,6 +541,7 @@  static const struct riscv_tune_param xiangshan_nanhu_tune_info = {
   3,						/* memory_cost */
   3,						/* fmv_cost */
   true,						/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_ZEXTW | RISCV_FUSE_ZEXTH,          /* fusible_ops */
@@ -549,6 +560,7 @@  static const struct riscv_tune_param generic_ooo_tune_info = {
   4,						/* memory_cost */
   4,						/* fmv_cost */
   false,					/* slow_unaligned_access */
+  true,						/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   true,						/* overlap_op_by_pieces */
   RISCV_FUSE_NOTHING,                           /* fusible_ops */
@@ -567,6 +579,7 @@  static const struct riscv_tune_param optimize_size_tune_info = {
   2,						/* memory_cost */
   8,						/* fmv_cost */
   false,					/* slow_unaligned_access */
+  false,					/* vector_unaligned_access */
   false,					/* use_divmod_expansion */
   false,					/* overlap_op_by_pieces */
   RISCV_FUSE_NOTHING,                           /* fusible_ops */
@@ -9536,6 +9549,12 @@  riscv_override_options_internal (struct gcc_options *opts)
   riscv_slow_unaligned_access_p = (cpu->tune_param->slow_unaligned_access
 				   || TARGET_STRICT_ALIGN);
 
+  /* By default, when -mno-vector-strict-align is not specified, do not allow
+     unaligned vector memory accesses except if -mtune's setting explicitly
+     allows it.  */
+  riscv_vector_unaligned_access_p = rvv_vector_strict_align == 0 ||
+    cpu->tune_param->vector_unaligned_access;
+
   /* Make a note if user explicitly passed -mstrict-align for later
      builtin macro generation.  Can't use target_flags_explicitly since
      it is set even for -mno-strict-align.  */
diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index d6b14c4d620..57910eecd3e 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -934,6 +934,10 @@  extern enum riscv_cc get_riscv_cc (const rtx use);
   || (riscv_microarchitecture == sifive_p400) \
   || (riscv_microarchitecture == sifive_p600))
 
+/* True if the target supports misaligned vector loads and stores.  */
+#define TARGET_VECTOR_MISALIGN_SUPPORTED \
+   riscv_vector_unaligned_access_p
+
 #define LOGICAL_OP_NON_SHORT_CIRCUIT 0
 
 /* Control the assembler format that we output.  */
@@ -1161,6 +1165,7 @@  while (0)
 #ifndef USED_FOR_TARGET
 extern const enum reg_class riscv_regno_to_class[];
 extern bool riscv_slow_unaligned_access_p;
+extern bool riscv_vector_unaligned_access_p;
 extern bool riscv_user_wants_strict_align;
 extern unsigned riscv_stack_boundary;
 extern unsigned riscv_bytes_per_vector_chunk;
diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index 87f58332016..edc569e9780 100644
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -128,6 +128,14 @@  mstrict-align
 Target Mask(STRICT_ALIGN) Save
 Do not generate unaligned memory accesses.
 
+mscalar-strict-align
+Target Mask(STRICT_ALIGN) Save
+Do not generate unaligned scalar memory accesses.
+
+mvector-strict-align
+Target Var(rvv_vector_strict_align) Init(1)
+Do not create element-misaligned vector memory accesses.
+
 Enum
 Name(code_model) Type(enum riscv_code_model)
 Known code models (for use with the -mcmodel= option):
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index c9d8f6b37b6..0091a0f4057 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -31099,6 +31099,28 @@  Do not or do generate unaligned memory accesses.  The default is set depending
 on whether the processor we are optimizing for supports fast unaligned access
 or not.
 
+@opindex mscalar-strict-align
+@opindex mno-scalar-strict-align
+@item -mscalar-strict-align
+@itemx -mno-scalar-strict-align
+Do not or do generate unaligned memory accesses.  The default is set depending
+on whether the processor we are optimizing for supports fast unaligned access
+or not.  This is an alias for @option{-mstrict-align}.
+
+@opindex mvector-strict-align
+@opindex mno-vector-strict-align
+@item -mvector-strict-align
+@itemx -mno-vector-strict-align
+Do not or do generate unaligned vector memory accesses.  The default is set
+to off unless the processor we are optimizing for explicitly supports
+element-misaligned vector memory access.
+
+@opindex mrvv-allow-misalign
+@item -mrvv-allow-misalign
+Allow the creation of element-misaligned vector loads and stores irrespective
+of the current uarch. The default is off.
+
+
 @opindex mcmodel=medlow
 @item -mcmodel=medlow
 Generate code for the medium-low code model. The program and its statically
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c
index 49ea3c2cf72..754f84ae0a0 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize -mrvv-max-lmul=dynamic" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize -mrvv-max-lmul=dynamic -mno-vector-strict-align" } */
 
 int
 x264_pixel_8x8 (unsigned char *pix1, unsigned char *pix2, int i_stride_pix2)
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-10.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-10.c
index 144479324d7..d0a0f4208ee 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-10.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-10.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m4 -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m4 -fno-schedule-insns -fno-schedule-insns2 -mno-vector-strict-align" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-11.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-11.c
index 13ae8bd3bcf..5a779a9ee75 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-11.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-11.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m8 -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m8 -fno-schedule-insns -fno-schedule-insns2 -mno-vector-strict-align" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-12.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-12.c
index 1f9fa48264e..e7e4e841bb8 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-12.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-12.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=dynamic -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=dynamic -fno-schedule-insns -fno-schedule-insns2 -mno-vector-strict-align" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-8.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-8.c
index ea6a7cbe2b1..0e5b4522de5 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-8.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-8.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mno-vector-strict-align" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-9.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-9.c
index cb4abeca989..5276e0b2f6c 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-9.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/vla_vs_vls-9.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m2" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -mrvv-max-lmul=m2 -mno-vector-strict-align" } */
 
 #include <stdint-gcc.h>
 
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/misalign-1.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/misalign-1.c
index 1a076cbcd0f..5184a295e16 100644
--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/misalign-1.c
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/misalign-1.c
@@ -1,5 +1,5 @@ 
 /* { dg-do compile } */
-/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -fno-schedule-insns -fno-schedule-insns2 -mrvv-max-lmul=m4 -fno-tree-loop-distribute-patterns" } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -fno-schedule-insns -fno-schedule-insns2 -mrvv-max-lmul=m4 -fno-tree-loop-distribute-patterns -mno-vector-strict-align" } */
 
 #include <stdlib.h>
 
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index f0f6da52275..e887efbb8f3 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -2034,7 +2034,7 @@  proc check_effective_target_riscv_zvfh_ok { } {
     # check if we can execute vector insns with the given hardware or
     # simulator
     set gcc_march [regsub {[[:alnum:]]*} [riscv_get_arch] &v]
-    if { [check_runtime ${gcc_march}_exec {
+    if { [check_runtime ${gcc_march}_zvfh_exec {
 	int main()
 	{
 	    asm ("vsetivli zero,8,e16,m1,ta,ma");
@@ -2047,6 +2047,29 @@  proc check_effective_target_riscv_zvfh_ok { } {
     return 0
 }
 
+# Return 1 if we can load a vector from a 1-byte aligned address.
+
+proc check_effective_target_riscv_v_misalign_ok { } {
+
+    if { ![check_effective_target_riscv_v_ok] } {
+	return 0
+    }
+
+    set gcc_march [riscv_get_arch]
+    if { [check_runtime ${gcc_march}_misalign_exec {
+	  int main() {
+	      unsigned char a[16]
+		= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
+	      asm ("vsetivli zero,7,e8,m1,ta,ma");
+	      asm ("addi a7,%0,1" : : "r" (a) : "a7" );
+	      asm ("vle8.v v8,0(a7)" : : : "v8");
+	      return 0; } } "-march=${gcc_march}"] } {
+	return 1
+    }
+
+    return 0
+}
+
 proc riscv_get_arch { } {
     set gcc_march ""
     # ??? do we neeed to add more extensions to the list below?
@@ -8139,7 +8162,6 @@  proc check_effective_target_vect_hw_misalign { } {
 	     || ([istarget mips*-*-*] && [et-is-effective-target mips_msa])
 	     || ([istarget s390*-*-*]
 		 && [check_effective_target_s390_vx])
-	     || ([istarget riscv*-*-*])
 	     || ([istarget loongarch*-*-*])
 	     || [istarget amdgcn*-*-*] } {
 	  return 1
@@ -8148,6 +8170,11 @@  proc check_effective_target_vect_hw_misalign { } {
 	     && ![check_effective_target_arm_vect_no_misalign] } {
 	  return 1
 	}
+	if { [istarget riscv*-*-*]
+	     && [check_effective_target_riscv_v_misalign_ok] } {
+	    return 1
+	}
+
         return 0
     }]
 }
@@ -11565,6 +11592,9 @@  proc check_vect_support_and_set_flags { } {
     } elseif [istarget riscv*-*-*] {
 	if [check_effective_target_riscv_v] {
 	    set dg-do-what-default run
+	    if [check_effective_target_riscv_v_misalign_ok] {
+		lappend DEFAULT_VECTCFLAGS "-mno-vector-strict-align"
+	    }
 	} else {
 	    foreach item [add_options_for_riscv_v ""] {
 		lappend DEFAULT_VECTCFLAGS $item