[Committed] PR rtl-optimization/108292: Revert "Improve ix86_expand_int_movcc to...

This reverts commit d0558f420b2a5692fd38ac76ffa97ae6c1726ed9.

2023-01-05  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
	PR rtl-optimization/108292
	* config/i386/i386-expand.cc (ix86_expand_int_movcc): Revert
	previous changes.

gcc/testsuite/ChangeLog
	PR rtl-optimization/108292
	* gcc.target/i386/cmov10.c: Remove test case.

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 4fd7c3ccd9189474e88c3370239ea2372f3b6b46..3eddbc9436093d90f0eb9a1ec8f4011f32a5cbe6 100644 (file)
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -3284,8 +3284,8 @@ ix86_expand_int_movcc (rtx operands[])
          || negate_cc_compare_p
          || ix86_expand_carry_flag_compare (code, op0, op1, &compare_op))
        {
-         /* Place comparison result in its own pseudo.  */
-         rtx tmp = gen_reg_rtx (mode);
+         /* Detect overlap between destination and compare sources.  */
+         rtx tmp = out;
 
          if (negate_cc_compare_p)
            {
@@ -3295,6 +3295,7 @@ ix86_expand_int_movcc (rtx operands[])
                emit_insn (gen_x86_negsi_ccc (gen_reg_rtx (SImode),
                                              gen_lowpart (SImode, op0)));
 
+             tmp = gen_reg_rtx (mode);
              if (mode == DImode)
                emit_insn (gen_x86_movdicc_0_m1_neg (tmp));
              else
@@ -3336,6 +3337,9 @@ ix86_expand_int_movcc (rtx operands[])
                }
              diff = ct - cf;
 
+             if (reg_overlap_mentioned_p (out, compare_op))
+               tmp = gen_reg_rtx (mode);
+
              if (mode == DImode)
                emit_insn (gen_x86_movdicc_0_m1 (tmp, flags, compare_op));
              else
@@ -3354,11 +3358,6 @@ ix86_expand_int_movcc (rtx operands[])
              tmp = emit_store_flag (tmp, code, op0, op1, VOIDmode, 0, -1);
            }
 
-         /* Add a REG_EQUAL note to allow condition to be shared.  */
-         rtx note = gen_rtx_fmt_ee (code, mode, op0, op1);
-         set_unique_reg_note (get_last_insn (), REG_EQUAL,
-                              gen_rtx_NEG (mode, note));
-
          if (diff == 1)
            {
              /*
@@ -3369,8 +3368,9 @@ ix86_expand_int_movcc (rtx operands[])
               * Size 5 - 8.
               */
              if (ct)
-               tmp = expand_simple_binop (mode, PLUS, tmp, GEN_INT (ct),
-                                          NULL_RTX, 1, OPTAB_DIRECT);
+               tmp = expand_simple_binop (mode, PLUS,
+                                          tmp, GEN_INT (ct),
+                                          copy_rtx (tmp), 1, OPTAB_DIRECT);
            }
          else if (cf == -1)
            {
@@ -3381,8 +3381,9 @@ ix86_expand_int_movcc (rtx operands[])
               *
               * Size 8.
               */
-             tmp = expand_simple_binop (mode, IOR, tmp, GEN_INT (ct),
-                                        NULL_RTX, 1, OPTAB_DIRECT);
+             tmp = expand_simple_binop (mode, IOR,
+                                        tmp, GEN_INT (ct),
+                                        copy_rtx (tmp), 1, OPTAB_DIRECT);
            }
          else if (diff == -1 && ct)
            {
@@ -3394,10 +3395,11 @@ ix86_expand_int_movcc (rtx operands[])
               *
               * Size 8 - 11.
               */
-             tmp = expand_simple_unop (mode, NOT, tmp, NULL_RTX, 1);
+             tmp = expand_simple_unop (mode, NOT, tmp, copy_rtx (tmp), 1);
              if (cf)
-               tmp = expand_simple_binop (mode, PLUS, tmp, GEN_INT (cf),
-                                          NULL_RTX, 1, OPTAB_DIRECT);
+               tmp = expand_simple_binop (mode, PLUS,
+                                          copy_rtx (tmp), GEN_INT (cf),
+                                          copy_rtx (tmp), 1, OPTAB_DIRECT);
            }
          else
            {
@@ -3415,18 +3417,22 @@ ix86_expand_int_movcc (rtx operands[])
                {
                  cf = ct;
                  ct = 0;
-                 tmp = expand_simple_unop (mode, NOT, tmp, NULL_RTX, 1);
+                 tmp = expand_simple_unop (mode, NOT, tmp, copy_rtx (tmp), 1);
                }
 
-             tmp = expand_simple_binop (mode, AND, tmp,
+             tmp = expand_simple_binop (mode, AND,
+                                        copy_rtx (tmp),
                                         gen_int_mode (cf - ct, mode),
-                                        NULL_RTX, 1, OPTAB_DIRECT);
+                                        copy_rtx (tmp), 1, OPTAB_DIRECT);
              if (ct)
-               tmp = expand_simple_binop (mode, PLUS, tmp, GEN_INT (ct),
-                                          NULL_RTX, 1, OPTAB_DIRECT);
+               tmp = expand_simple_binop (mode, PLUS,
+                                          copy_rtx (tmp), GEN_INT (ct),
+                                          copy_rtx (tmp), 1, OPTAB_DIRECT);
            }
 
-         emit_move_insn (out, tmp);
+         if (!rtx_equal_p (tmp, out))
+           emit_move_insn (copy_rtx (out), copy_rtx (tmp));
+
          return true;
        }
 

diff --git a/gcc/testsuite/gcc.target/i386/cmov10.c b/gcc/testsuite/gcc.target/i386/cmov10.c
deleted file mode 100644 (file)
index 142b4d7..0000000
--- a/gcc/testsuite/gcc.target/i386/cmov10.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-O2" } */
-int a, b, c, d;
-
-int foo(int x)
-{
-    if (x == 0) {
-        a = 3;
-        b = 1;
-        c = 4;
-        d = 1;
-    } else {
-        a = 5;
-        b = 9;
-        c = 2;
-        d = 7;
-    }
-    return x;
-}
-/* { dg-final { scan-assembler-times "cmpl" 1 } } */
-/* { dg-final { scan-assembler-times "sbbl" 1 } } */