From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 4 Oct 2024 10:36:52 +0000 (+0200)
Subject: i386: Fix up *minmax<mode>3_2 splitter [PR116925]
X-Git-Tag: basepoints/gcc-16~5491
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=67b750c20e1f9428ef89a6fed0103e912bea8679;p=thirdparty%2Fgcc.git

i386: Fix up *minmax<mode>3_2 splitter [PR116925]

While *minmax<mode>3_1 correctly uses
   if (MEM_P (operands[1]))
     operands[1] = force_reg (<MODE>mode, operands[1]);
to ensure operands[1] is not a MEM, *minmax<mode>3_2 does it wrongly
by calling force_reg but ignoring its return value.

The following borderingly obvious patch fixes that.

Didn't find similar other errors in the backend with force_reg calls.

2024-10-04  Jakub Jelinek  <jakub@redhat.com>

	PR target/116925
	* config/i386/sse.md (*minmax<mode>3_2): Assign force_reg result
	back to operands[2] instead of throwing it away.

	* g++.target/i386/avx-pr116925.C: New test.
---

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 183c1953f91..d6e2135423d 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -3269,7 +3269,7 @@
      u = UNSPEC_IEEE_MAX;
 
    if (MEM_P (operands[2]))
-     force_reg (<MODE>mode, operands[2]);
+     operands[2] = force_reg (<MODE>mode, operands[2]);
    rtvec v = gen_rtvec (2, operands[2], operands[1]);
    rtx tmp = gen_rtx_UNSPEC (<MODE>mode, v, u);
    emit_move_insn (operands[0], tmp);
diff --git a/gcc/testsuite/g++.target/i386/avx-pr116925.C b/gcc/testsuite/g++.target/i386/avx-pr116925.C
new file mode 100644
index 00000000000..b2d6fc1856b
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/avx-pr116925.C
@@ -0,0 +1,12 @@
+// PR target/116925
+// { dg-do compile }
+// { dg-options "-O2 -mavx -ffloat-store" }
+
+typedef float V __attribute__((vector_size (16)));
+V a, b, c;
+
+void
+foo ()
+{
+  c = a > b ? a : b;
+}