From: Richard Biener <rguenther@suse.de>
Date: Wed, 9 Feb 2022 07:48:35 +0000 (+0100)
Subject: target/104453 - guard call folding with NULL LHS
X-Git-Tag: releases/gcc-10.4.0~370
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=807bfd4357609655c81d0a3282b699b10e7aeb5a;p=thirdparty%2Fgcc.git

target/104453 - guard call folding with NULL LHS

This guards shift builtin folding to do nothing when there is
no LHS, similar to what other foldings do.

2022-02-09  Richard Biener  <rguenther@suse.de>

	PR target/104453
	* config/i386/i386.c (ix86_gimple_fold_builtin): Guard shift
	folding for NULL LHS.

	* gcc.target/i386/pr104453.c: New testcase.

(cherry picked from commit 1c827873ed283df282f2df11dfe0ff607e07dab3)
---

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index cec0340ec51f..19cb5d40c694 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -17848,6 +17848,8 @@ ix86_gimple_fold_builtin (gimple_stmt_iterator *gsi)
 
     do_shift:
       gcc_assert (n_args >= 2);
+      if (!gimple_call_lhs (stmt))
+	break;
       arg0 = gimple_call_arg (stmt, 0);
       arg1 = gimple_call_arg (stmt, 1);
       if (n_args > 2)
diff --git a/gcc/testsuite/gcc.target/i386/pr104453.c b/gcc/testsuite/gcc.target/i386/pr104453.c
new file mode 100644
index 000000000000..325cedf0e2c9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr104453.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx512f" } */
+
+typedef short __attribute__((__vector_size__ (32))) V;
+V g;
+
+void
+foo (void)
+{
+  __builtin_ia32_psrawi256 (g, 0);
+}