Canonicalize ASM_OPERANDS inside PARALLEL during CSE

[Eric Botcazou]

canonicalize_insn attempts to replace pseudo-registers with the canonical ones 
during the CSE pass and it does so inside ASM_OPERANDS (only for the inputs) 
and inside PARALLELs, but not inside ASM_OPERANDS which are themselves inside 
a PARALLEL.  The latter case occurs for targets that automatically clobber the 
CC register for inline assembly statements, for example Visium and x86.

Tested on x86_64-suse-linux, applied on the mainline.


2016-06-21  Eric Botcazou  <ebotca...@adacore.com>

        * cse.c (canon_asm_operands): New function extracted from...
        (canonicalize_insn): ...here.  Call it to canonicalize an ASM_OPERANDS
        either standalone or member of a PARALLEL.

-- 
Eric Botcazou
Index: cse.c
===================================================================
--- cse.c	(revision 237571)
+++ cse.c	(working copy)
@@ -4298,6 +4298,22 @@ find_sets_in_insn (rtx_insn *insn, struc
   return n_sets;
 }
 
+/* Subroutine of canonicalize_insn.  X is an ASM_OPERANDS in INSN.  */
+
+static void
+canon_asm_operands (rtx x, rtx_insn *insn)
+{
+  for (int i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
+    {
+      rtx input = ASM_OPERANDS_INPUT (x, i);
+      if (!(REG_P (input) && HARD_REGISTER_P (input)))
+	{
+	  input = canon_reg (input, insn);
+	  validate_change (insn, &ASM_OPERANDS_INPUT (x, i), input, 1);
+	}
+    }
+}
+
 /* Where possible, substitute every register reference in the N_SETS
    number of SETS in INSN with the canonical register.
 
@@ -4361,17 +4377,7 @@ canonicalize_insn (rtx_insn *insn, struc
     /* Canonicalize a USE of a pseudo register or memory location.  */
     canon_reg (x, insn);
   else if (GET_CODE (x) == ASM_OPERANDS)
-    {
-      for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
-	{
-	  rtx input = ASM_OPERANDS_INPUT (x, i);
-	  if (!(REG_P (input) && REGNO (input) < FIRST_PSEUDO_REGISTER))
-	    {
-	      input = canon_reg (input, insn);
-	      validate_change (insn, &ASM_OPERANDS_INPUT (x, i), input, 1);
-	    }
-	}
-    }
+    canon_asm_operands (x, insn);
   else if (GET_CODE (x) == CALL)
     {
       canon_reg (x, insn);
@@ -4400,6 +4406,8 @@ canonicalize_insn (rtx_insn *insn, struc
 		   && ! (REG_P (XEXP (y, 0))
 			 && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER))
 	    canon_reg (y, insn);
+	  else if (GET_CODE (y) == ASM_OPERANDS)
+	    canon_asm_operands (y, insn);
 	  else if (GET_CODE (y) == CALL)
 	    {
 	      canon_reg (y, insn);