[PATCH][x86_64] Fix PR87853, _mm_cmpgt_epi8 broken with -funsigned-char

[Terry Guo]

Hi there,

This patch intends to fix PR87853 by involving a new 'signed char'
vector type to avoid the impact of option -funsigned-char. Tested with
bootstrap and regression tests on x86_64. No regressions.

Is it OK to trunk and release branch?

BR,
Terry

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ac121a8..dc10a11 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2018-11-05  Xuepeng Guo  <xuepeng.guo@intel.com>
+
+       PR target/87853
+       * config/i386/emmintrin.h (__v16qs): New to cope with option
+       -funsigned-char.
+       (_mm_cmpeq_epi8): Replace __v16qi with __v16qs.
+       (_mm_cmplt_epi8): Likewise.
+       (_mm_cmpgt_epi8): Likewise.
+
 2018-11-04  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR tree-optimization/86572
diff --git a/gcc/config/i386/emmintrin.h b/gcc/config/i386/emmintrin.h
index 7a6ff80..3c1f04b 100644
--- a/gcc/config/i386/emmintrin.h
+++ b/gcc/config/i386/emmintrin.h
@@ -45,6 +45,7 @@ typedef unsigned int __v4su __attribute__
((__vector_size__ (16)));
 typedef short __v8hi __attribute__ ((__vector_size__ (16)));
 typedef unsigned short __v8hu __attribute__ ((__vector_size__ (16)));
 typedef char __v16qi __attribute__ ((__vector_size__ (16)));
+typedef signed char __v16qs __attribute__ ((__vector_size__ (16)));
 typedef unsigned char __v16qu __attribute__ ((__vector_size__ (16)));

 /* The Intel API is flexible enough that we must allow aliasing with other
@@ -1295,7 +1296,7 @@ _mm_xor_si128 (__m128i __A, __m128i __B)
 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))
 _mm_cmpeq_epi8 (__m128i __A, __m128i __B)
 {
-  return (__m128i) ((__v16qi)__A == (__v16qi)__B);
+  return (__m128i) ((__v16qs)__A == (__v16qs)__B);
 }

 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))
@@ -1313,7 +1314,7 @@ _mm_cmpeq_epi32 (__m128i __A, __m128i __B)
 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))
 _mm_cmplt_epi8 (__m128i __A, __m128i __B)
 {
-  return (__m128i) ((__v16qi)__A < (__v16qi)__B);
+  return (__m128i) ((__v16qs)__A < (__v16qs)__B);
 }

 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))
@@ -1331,7 +1332,7 @@ _mm_cmplt_epi32 (__m128i __A, __m128i __B)
 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))
 _mm_cmpgt_epi8 (__m128i __A, __m128i __B)
 {
-  return (__m128i) ((__v16qi)__A > (__v16qi)__B);
+  return (__m128i) ((__v16qs)__A > (__v16qs)__B);
 }

 extern __inline __m128i __attribute__((__gnu_inline__,
__always_inline__, __artificial__))