[gcc r15-993] i386: Force operand 1 of bswapsi2 to a register for !TARGET_BSWAP [PR115321]

[Uros Bizjak via Gcc-cvs]

https://gcc.gnu.org/g:6ab5145825ca7e96fcbe3aa505d42e4ae8f81009

commit r15-993-g6ab5145825ca7e96fcbe3aa505d42e4ae8f81009
Author: Uros Bizjak <ubiz...@gmail.com>
Date:   Mon Jun 3 15:48:18 2024 +0200

    i386: Force operand 1 of bswapsi2 to a register for !TARGET_BSWAP [PR115321]
    
            PR target/115321
    
    gcc/ChangeLog:
    
            * config/i386/i386.md (bswapsi2): Force operand 1
            to a register also for !TARGET_BSWAP.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/pr115321.c: New test.

Diff:
---
 gcc/config/i386/i386.md                  | 21 +++++++++++----------
 gcc/testsuite/gcc.target/i386/pr115321.c |  4 ++++
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 2c95395b7be..ef83984d00e 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -21193,18 +21193,19 @@
        (bswap:SI (match_operand:SI 1 "nonimmediate_operand")))]
   ""
 {
-  if (TARGET_MOVBE)
-    ;
-  else if (TARGET_BSWAP)
-    operands[1] = force_reg (SImode, operands[1]);
-  else
+  if (!TARGET_MOVBE)
     {
-      rtx x = gen_reg_rtx (SImode);
+      operands[1] = force_reg (SImode, operands[1]);
 
-      emit_insn (gen_bswaphisi2_lowpart (x, operands[1]));
-      emit_insn (gen_rotlsi3 (x, x, GEN_INT (16)));
-      emit_insn (gen_bswaphisi2_lowpart (operands[0], x));
-      DONE;
+      if (!TARGET_BSWAP)
+       {
+         rtx x = gen_reg_rtx (SImode);
+
+         emit_insn (gen_bswaphisi2_lowpart (x, operands[1]));
+         emit_insn (gen_rotlsi3 (x, x, GEN_INT (16)));
+         emit_insn (gen_bswaphisi2_lowpart (operands[0], x));
+         DONE;
+       }
     }
 })
 
diff --git a/gcc/testsuite/gcc.target/i386/pr115321.c 
b/gcc/testsuite/gcc.target/i386/pr115321.c
new file mode 100644
index 00000000000..0ddab9bd7a5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr115321.c
@@ -0,0 +1,4 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-march=i386" } */
+
+unsigned foo (unsigned x) { return __builtin_bswap32 (x); }