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[pushed,PR109052] LRA: Implement commutative operands exchange for combining secondary memory reload and original insn

Message ID 006d8e44-ade0-afc3-453f-05ff9d8e7f7a@redhat.com
State New
Headers show
Series [pushed,PR109052] LRA: Implement commutative operands exchange for combining secondary memory reload and original insn | expand

Commit Message

Vladimir Makarov March 31, 2023, 3:06 p.m. UTC 
This is one more patch for

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109052

The patch adds trying commutative operands exchange for recently 
implemented combining secondary memory reload and original insn:

The patch was successfully bootstrapped and tested on x86_64.
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Patch

commit 378d19cfebfa2bc4f693dfc9e6f0dd993e7c45f7
Author: Vladimir N. Makarov <vmakarov@redhat.com>
Date:   Fri Mar 31 11:04:44 2023 -0400

    LRA: Implement commutative operands exchange for combining secondary memory reload and original insn
    
    The patch implements trying commutative operands exchange for
    combining secondary memory reload and original insn.
    
            PR rtl-optimization/109052
    
    gcc/ChangeLog:
    
            * lra-constraints.cc: (combine_reload_insn): New function.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/pr109052-2.c: New.

diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index 405b8b92f5e..ff4e8f06063 100644
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -5061,7 +5061,23 @@  combine_reload_insn (rtx_insn *from, rtx_insn *to)
       curr_insn = to;
       curr_id = lra_get_insn_recog_data (curr_insn);
       curr_static_id = curr_id->insn_static_data;
-      ok_p = !curr_insn_transform (true);
+      for (bool swapped_p = false;;)
+	{
+	  ok_p = !curr_insn_transform (true);
+	  if (ok_p || curr_static_id->commutative < 0)
+	    break;
+	  swap_operands (curr_static_id->commutative);
+	  if (lra_dump_file != NULL)
+	    {
+	      fprintf (lra_dump_file,
+		       "    Swapping %scombined insn operands:\n",
+		       swapped_p ? "back " : "");
+	      dump_insn_slim (lra_dump_file, to);
+	    }
+	  if (swapped_p)
+	    break;
+	  swapped_p = true;
+	}
       curr_insn = saved_insn;
       curr_id = lra_get_insn_recog_data (curr_insn);
       curr_static_id = curr_id->insn_static_data;
diff --git a/gcc/testsuite/gcc.target/i386/pr109052-2.c b/gcc/testsuite/gcc.target/i386/pr109052-2.c
new file mode 100644
index 00000000000..337d1f49c2b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr109052-2.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mfpmath=both -mavx -fno-math-errno" } */
+
+double foo (double a, double b)
+{
+  double z = __builtin_fmod (a, 3.14);
+  return z * b;
+}
+
+/* { dg-final { scan-assembler-not "vmulsd\[ \t]\+%xmm\[0-9]\+, %xmm\[0-9]\+, %xmm\[0-9]\+"} } */