Re: [Patch] Bug 88521 - gcc 9.0 from r266355 miscompile x265 for mingw-w64 target

[Jakub Jelinek <jakub@redhat.com>]

On Thu, Dec 20, 2018 at 01:42:15PM +0530, Lokesh Janghel wrote:
> Hi Mateuszb,
> 
> I tested with your proposition patch and it is working right.
> I also added the patch with test case.
> Please let me know your thoughts/suggestions.

ChangeLog entry is missing, please write it (and mention there
Mateusz's name/mail as he wrote the i386.c part).

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index b3c8676..e54c489 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -9063,6 +9063,13 @@ function_value_ms_64 (machine_mode orig_mode, machine_mode mode,
 	      && !COMPLEX_MODE_P (mode))
 	    regno = FIRST_SSE_REG;
 	  break;
+	case 8:
+	case 4:
+	  if (valtype != NULL_TREE && AGGREGATE_TYPE_P (valtype))
+	    break;
+	  if (mode == SFmode || mode == DFmode)
+	    regno = FIRST_SSE_REG;
+	  break;
 	default:
 	  break;
         }
diff --git a/gcc/testsuite/gcc.target/i386/pr88521.c b/gcc/testsuite/gcc.target/i386/pr88521.c
new file mode 100644
index 0000000..f42703a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr88521.c
@@ -0,0 +1,30 @@
+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "movl\[^\n\r]*, %eax|mov\[ \t]*eax," 1 } } */

You try here to handle both -masm=att and -masm=intel

+/* { dg-final { scan-assembler-times "movss\[^\n\r]*, %xmm" 1 } } */
+/* { dg-final { scan-assembler-times "movsd\[^\n\r]*, %xmm" 1 } } */

but not here.  For that it would need to be "movss\[^\n\r]*(?:, %xmm|xmm, )"
and similarly for movsd (please verify with
make check-gcc RUNTESTFLAGS='--target_board=unix\{-m32/-masm=att,-m32/-masm=intel,-m64/-masm=att,-m64/-masm=intel\} i386.exp=pr88521.c'

I'll defer the final review to Uros.

	Jakub