testsuite: Fix up pr111754.c test

On Tue, Nov 28, 2023 at 03:56:47PM +0800, juzhe.zhong@rivai.ai wrote:
> Hi, there is a regression in RISC-V caused by this patch:
>
> FAIL: gcc.dg/vect/pr111754.c -flto -ffat-lto-objects  scan-tree-dump optimized "return { 0.0, 9.0e\\+0, 0.0, 0.0 }"
> FAIL: gcc.dg/vect/pr111754.c scan-tree-dump optimized "return { 0.0, 9.0e\\+0, 0.0, 0.0 }"
>
> I have checked the dump is :
> F foo (F a, F b)
> {
>   <bb 2> [local count: 1073741824]:
>   <retval> = { 0.0, 9.0e+0, 0.0, 0.0 };
>   return <retval>;
>
> }
>
> The dump IR seems reasonable to me.
> I wonder whether we should walk around in RISC-V backend to generate the same IR as ARM SVE ?
> Or we should adjust the test ?

Note, the test also FAILs on i686-linux (but not e.g. on x86_64-linux):
/home/jakub/src/gcc/obj67/gcc/xgcc -B/home/jakub/src/gcc/obj67/gcc/ /home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c -fdiagnostics-plain-output -O2 -fdump-tree-optimized -S
+-o pr111754.s
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c: In function 'foo':
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c:7:1: warning: SSE vector return without SSE enabled changes the ABI [-Wpsabi]
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c:6:3: note: the ABI for passing parameters with 16-byte alignment has changed in GCC 4.6
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c:6:3: warning: SSE vector argument without SSE enabled changes the ABI [-Wpsabi]
FAIL: gcc.dg/vect/pr111754.c (test for excess errors)
Excess errors:
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c:7:1: warning: SSE vector return without SSE enabled changes the ABI [-Wpsabi]
/home/jakub/src/gcc/gcc/testsuite/gcc.dg/vect/pr111754.c:6:3: warning: SSE vector argument without SSE enabled changes the ABI [-Wpsabi]

PASS: gcc.dg/vect/pr111754.c scan-tree-dump-not optimized "VEC_PERM_EXPR"
FAIL: gcc.dg/vect/pr111754.c scan-tree-dump optimized "return { 0.0, 9.0e\\+0, 0.0, 0.0 }"

So, I think it is wrong to specify
/* { dg-options "-O2 -fdump-tree-optimized" } */
in the test, should be dg-additional-options instead, so that it gets
the implied vector compilation options e.g. for i686-linux (-msse2 in that
case at least), question is if -Wno-psabi should be added as well or not,
and certainly the scan-tree-dump needs to be guarded by appropriate
vect_* effective target (but dunno which, one which asserts support for
V4SFmode and returning it).
Alternatively, perhaps don't check optimized dump but some earlier one
before generic vector lowering, then hopefully it could match on all
targets?  Maybe with the <retval> = ... vs. return ... variants.

2023-11-28  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/111754
	* gcc.dg/vect/pr111754.c: Use dg-additional-options rather than
	dg-options, add -Wno-psabi and use -fdump-tree-forwprop1 rather than
	-fdump-tree-optimized.  Scan forwprop1 dump rather than optimized and
	scan for either direct return or setting of <retval> to the vector.

1 files changed, 4 insertions, 3 deletions

diff --git a/gcc/testsuite/gcc.dg/vect/pr111754.c b/gcc/testsuite/gcc.dg/vect/pr111754.c
index 7c1c168..014472f 100644
--- a/gcc/testsuite/gcc.dg/vect/pr111754.c
+++ b/gcc/testsuite/gcc.dg/vect/pr111754.c
@@ -1,5 +1,6 @@
+/* PR middle-end/111754 */
 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-additional-options "-O2 -fdump-tree-forwprop1 -Wno-psabi" } */
 
 typedef float __attribute__((__vector_size__ (16))) F;
 
@@ -9,5 +10,5 @@ F foo (F a, F b)
   return __builtin_shufflevector (v, v, 1, 0, 1, 2);
 }
 
-/* { dg-final { scan-tree-dump-not "VEC_PERM_EXPR" "optimized" } } */
-/* { dg-final { scan-tree-dump "return \{ 0.0, 9.0e\\+0, 0.0, 0.0 \}" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "VEC_PERM_EXPR" "forwprop1" } } */
+/* { dg-final { scan-tree-dump "(return|<retval> =) \{ 0.0, 9.0e\\+0, 0.0, 0.0 \}" "forwprop1" } } */