From: Xi Ruoyao <xry111@xry111.site>
Date: Tue, 6 Feb 2024 09:49:50 +0000 (+0800)
Subject: testsuite: Add a test case for negating FP vectors containing zeros
X-Git-Tag: basepoints/gcc-15~422
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26a723625bb63e42b8c78bbce52ba0286eefda1c;p=thirdparty%2Fgcc.git

testsuite: Add a test case for negating FP vectors containing zeros

Recently I've fixed two wrong FP vector negate implementation which
caused wrong sign bits in zeros in targets (r14-8786 and r14-8801).  To
prevent a similar issue from happening again, add a test case.

Tested on x86_64 (with SSE2, AVX, AVX2, and AVX512F), AArch64, MIPS
(with MSA), LoongArch (with LSX and LASX).

gcc/testsuite:

	* gcc.dg/vect/vect-neg-zero.c: New test.
---

diff --git a/gcc/testsuite/gcc.dg/vect/vect-neg-zero.c b/gcc/testsuite/gcc.dg/vect/vect-neg-zero.c
new file mode 100644
index 000000000000..21fa00cfa155
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-neg-zero.c
@@ -0,0 +1,38 @@
+/* { dg-add-options ieee } */
+/* { dg-additional-options "-fno-associative-math -fsigned-zeros" } */
+
+double x[4] = {-0.0, 0.0, -0.0, 0.0};
+float y[8] = {-0.0, 0.0, -0.0, 0.0, -0.0, -0.0, 0.0, 0.0};
+
+static __attribute__ ((always_inline)) inline void
+test (int factor)
+{
+  double a[4];
+  float b[8];
+
+  asm ("" ::: "memory");
+
+  for (int i = 0; i < 2 * factor; i++)
+    a[i] = -x[i];
+
+  for (int i = 0; i < 4 * factor; i++)
+    b[i] = -y[i];
+
+#pragma GCC novector
+  for (int i = 0; i < 2 * factor; i++)
+    if (__builtin_signbit (a[i]) == __builtin_signbit (x[i]))
+      __builtin_abort ();
+
+#pragma GCC novector
+  for (int i = 0; i < 4 * factor; i++)
+    if (__builtin_signbit (b[i]) == __builtin_signbit (y[i]))
+      __builtin_abort ();
+}
+
+int
+main (void)
+{
+  test (1);
+  test (2);
+  return 0;
+}