Allow -mno-evex512 usagedevel/ix86/evex512

gcc/ChangeLog:

	* config/i386/i386.opt: Allow -mno-evex512.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/noevex512-1.c: New test.
	* gcc.target/i386/noevex512-2.c: Ditto.
	* gcc.target/i386/noevex512-3.c: Ditto.

4 files changed, 40 insertions, 1 deletions

diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 6d8601b1f75..34fc167af82 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -1312,5 +1312,5 @@ Target Alias(mtune-ctrl=, use_scatter, ^use_scatter)
 Enable vectorization for scatter instruction.
 
 mevex512
-Target RejectNegative Mask(ISA2_EVEX512) Var(ix86_isa_flags2) Save
+Target Mask(ISA2_EVEX512) Var(ix86_isa_flags2) Save
 Support 512 bit vector built-in functions and code generation.
diff --git a/gcc/testsuite/gcc.target/i386/noevex512-1.c b/gcc/testsuite/gcc.target/i386/noevex512-1.c
new file mode 100644
index 00000000000..7fd45f15be6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/noevex512-1.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O0 -march=x86-64 -mavx512f -mno-evex512 -Wno-psabi" } */
+/* { dg-final { scan-assembler-not ".%zmm" } } */
+
+typedef double __m512d __attribute__ ((__vector_size__ (64), __may_alias__));
+
+__m512d
+foo ()
+{
+  __m512d a, b;
+  a = a + b;
+  return a;
+}
diff --git a/gcc/testsuite/gcc.target/i386/noevex512-2.c b/gcc/testsuite/gcc.target/i386/noevex512-2.c
new file mode 100644
index 00000000000..1c206e385d0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/noevex512-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=x86-64 -mavx512bw -mno-evex512" } */
+
+#include <immintrin.h>
+
+long long
+foo (long long c)
+{
+  register long long a __asm ("k7") = c;
+  long long b = foo (a);
+  asm volatile ("" : "+k" (b)); /* { dg-error "inconsistent operand constraints in an 'asm'" } */
+  return b;
+}
diff --git a/gcc/testsuite/gcc.target/i386/noevex512-3.c b/gcc/testsuite/gcc.target/i386/noevex512-3.c
new file mode 100644
index 00000000000..10e00c2d61c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/noevex512-3.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-march=x86-64 -Wno-psabi -mavx512f" } */
+/* { dg-final { scan-assembler-not ".%zmm" } } */
+
+typedef double __m512d __attribute__ ((__vector_size__ (64), __may_alias__));
+
+__attribute__ ((target ("no-evex512"))) __m512d
+foo ()
+{
+  __m512d a, b;
+  a = a + b;
+  return a;
+}