From: Thomas Schwinge <thomas@codesourcery.com>
Date: Sat, 15 Oct 2022 22:07:20 +0000 (+0200)
Subject: Restore 'libgomp.oacc-c-c++-common/nvptx-sese-1.c' SESE regions checking [PR107195... 
X-Git-Tag: basepoints/gcc-14~3773
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9de836c2b22f878cff592b96e11c1b95d4d36ee;p=thirdparty%2Fgcc.git

Restore 'libgomp.oacc-c-c++-common/nvptx-sese-1.c' SESE regions checking [PR107195, PR107344]

That is, adjust for optimization introduced with recent
commit r13-3217-gc4d15dddf6b9eacb36f535807ad2ee364af46e04
"[PR107195] Set range to zero when nonzero mask is 0", where GCC now
understands that after 'r *= 2;', 'r & 1' will never hold here, and thus
transforms/optimizes/"disturbs" the original code such that GCC/nvptx's later
"Neuter whole SESE regions" optimization no longer is applicable to it:

    UNSUPPORTED: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c -DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O0
    PASS: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c -DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2  (test for excess errors)
    PASS: libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c -DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2  execution test
    [-PASS:-]{+FAIL:+} libgomp.oacc-c/../libgomp.oacc-c-c++-common/nvptx-sese-1.c -DACC_DEVICE_TYPE_nvidia=1 -DACC_MEM_SHARED=0 -foffload=nvptx-none  -O2   scan-nvptx-none-offload-rtl-dump mach "SESE regions:.* [0-9]+{[0-9]+->[0-9]+(\\.[0-9]+)+}"

Same for C++.

It's unclear to me if this is an actual "problem", which optimization is "more
important", so I've filed PR107344 "GCC/nvptx SESE region optimization" to
capture this question, and here restore what we intend to be testing (to my
understanding) in 'libgomp.oacc-c-c++-common/nvptx-sese-1.c'.

	PR tree-optimization/107195
	PR target/107344
	libgomp/
	* testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c: Restore SESE
	regions checking.
---

diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c
index 9583265c7751..6507e1affb0e 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/nvptx-sese-1.c
@@ -22,7 +22,7 @@ int main ()
     if (foo (r))
       r *= 2;
 
-    if (r & 1) /* to here. */
+    if (r & 8) /* to here. */
 #pragma acc loop vector reduction (+:r)
       for (int i = 00; i < 40; i++)
 	r += i;