[2/4] sparc: Skip all empty assembly statements

Message ID 20210915093610.3112669-4-cederman@gaisler.com
State Changes Requested
Headers
Series sparc: Print out bit names for LEON and LEON3 with -mdebug |

Commit Message

Daniel Cederman Sept. 15, 2021, 9:36 a.m. UTC
  This version detects multiple empty assembly statements in a row and also
detects non-memory barrier empty assembly statements (__asm__("")). It
can be used instead of next_active_insn().

gcc/ChangeLog:

        * config/sparc/sparc.c (next_active_non_empty_insn): New function
        that returns next active non empty assembly instruction.
        (sparc_do_work_around_errata): Use new function.
---
 gcc/config/sparc/sparc.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)
  

Comments

Eric Botcazou Sept. 15, 2021, 10:31 a.m. UTC | #1
> gcc/ChangeLog:
> 
>         * config/sparc/sparc.c (next_active_non_empty_insn): New function
>         that returns next active non empty assembly instruction.
>         (sparc_do_work_around_errata): Use new function.

OK everywhere, modulo a couple of nits:

> +rtx_insn *
> +next_active_non_empty_insn (rtx_insn *insn)
> +{
> +  insn = next_active_insn (insn);
> +
> +  while (insn
> +	 && ((GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE)

Superfluous parentheses 

> +	     || (GET_CODE (PATTERN (insn)) == ASM_INPUT)

Likewise.

> +	     || (USEFUL_INSN_P (insn)
> +		 && (asm_noperands (PATTERN (insn))>=0)

Missing spaces around >=

> +    {
> +      insn = next_active_insn (insn);
> +    }

Superfluous curly braces, even for readability.
  

Patch

diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index fa78e0dc739..b087c5b3fc8 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -1082,6 +1082,26 @@  load_insn_p (rtx_insn *insn)
    && GET_CODE (PATTERN (INSN)) != USE					\
    && GET_CODE (PATTERN (INSN)) != CLOBBER)
 
+rtx_insn *
+next_active_non_empty_insn (rtx_insn *insn)
+{
+  insn = next_active_insn (insn);
+
+  while (insn
+	 && ((GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE)
+	     || (GET_CODE (PATTERN (insn)) == ASM_INPUT)
+	     || (USEFUL_INSN_P (insn)
+		 && (asm_noperands (PATTERN (insn))>=0)
+		 && !strcmp (decode_asm_operands (PATTERN (insn),
+						  NULL, NULL, NULL,
+						  NULL, NULL), ""))))
+    {
+      insn = next_active_insn (insn);
+    }
+
+  return insn;
+}
+
 static unsigned int
 sparc_do_work_around_errata (void)
 {
@@ -1139,7 +1159,7 @@  sparc_do_work_around_errata (void)
 		emit_insn_before (gen_nop (), target);
 	    }
 
-	  next = next_active_insn (insn);
+	  next = next_active_non_empty_insn (insn);
 	  if (!next)
 	    break;
 
@@ -1242,23 +1262,12 @@  sparc_do_work_around_errata (void)
 	  rtx_insn *after;
 	  int i;
 
-	  next = next_active_insn (insn);
+	  next = next_active_non_empty_insn (insn);
 	  if (!next)
 	    break;
 
 	  for (after = next, i = 0; i < 2; i++)
 	    {
-	      /* Skip empty assembly statements.  */
-	      if ((GET_CODE (PATTERN (after)) == UNSPEC_VOLATILE)
-		  || (USEFUL_INSN_P (after)
-		      && (asm_noperands (PATTERN (after))>=0)
-		      && !strcmp (decode_asm_operands (PATTERN (after),
-						       NULL, NULL, NULL,
-						       NULL, NULL), "")))
-		after = next_active_insn (after);
-	      if (!after)
-		break;
-
 	      /* If the insn is a branch, then it cannot be problematic.  */
 	      if (!NONJUMP_INSN_P (after)
 		  || GET_CODE (PATTERN (after)) == SEQUENCE)
@@ -1283,7 +1292,7 @@  sparc_do_work_around_errata (void)
 		      && (MEM_P (SET_DEST (set)) || mem_ref (SET_SRC (set))))
 		    break;
 
-		  after = next_active_insn (after);
+		  after = next_active_non_empty_insn (after);
 		  if (!after)
 		    break;
 		}