Fix wrong code due to vec_merge + pcmp to blendvb splitter.

gcc/ChangeLog:

	PR target/112443
	* config/i386/sse.md (*avx2_pcmp<mode>3_4): Fix swap condition
	from LT to GT since there's not in the pattern.
	(*avx2_pcmp<mode>3_5): Ditto.

gcc/testsuite/ChangeLog:

	* g++.target/i386/pr112443.C: New test.

(cherry picked from commit 9a0cc04)

gcc/config/i386/sse.md

@@ -16358,7 +16358,7 @@
 	     (match_dup 4))]
 	     UNSPEC_BLENDV))]
 {
-  if (INTVAL (operands[5]) == 1)
+  if (INTVAL (operands[5]) == 5)
     std::swap (operands[1], operands[2]);
   operands[3] = gen_lowpart (<MODE>mode, operands[3]);
 })
@@ -16388,7 +16388,7 @@
 	     (match_dup 4))]
 	     UNSPEC_BLENDV))]
 {
-  if (INTVAL (operands[5]) == 1)
+  if (INTVAL (operands[5]) == 5)
     std::swap (operands[1], operands[2]);
 })
 

gcc/testsuite/g++.target/i386/pr112443.C

@@ -0,0 +1,108 @@
+/* { dg-do run } */
+/* { dg-require-effective-target avx512bw } */
+/* { dg-require-effective-target avx512vl } */
+/* { dg-options "-O2 -std=c++17 -mavx512bw -mavx512vl" } */
+
+#include <cstdint>
+#include <x86intrin.h>
+#include <functional>
+#include <ostream>
+
+#define AVX512BW
+#define AVX512VL
+
+#include "avx512f-helper.h"
+
+struct TensorIteratorBase{
+  char* in;
+  char* out;
+
+  void for_each(std::function<void(char*, char*, int64_t size)> loop){
+    loop(out, in, 32);
+  }    
+};
+
+class Vectorized {
+protected:
+  __m256i values;
+
+  static inline __m256i invert(const __m256i& v) {
+    const auto ones = _mm256_set1_epi64x(-1);
+    return _mm256_xor_si256(ones, v);
+  }
+public:
+  operator __m256i() const {
+    return values;
+  }
+
+  static constexpr int size() {
+    return 32;
+  }
+
+  Vectorized() {}
+  Vectorized(__m256i v) : values(v) {}
+  Vectorized(uint8_t v) { values = _mm256_set1_epi8(v); }
+  static Vectorized blendv(const Vectorized& a, const Vectorized& b,
+			   const Vectorized& mask) {
+    return _mm256_blendv_epi8(a, b, mask);
+  }
+  static Vectorized loadu(const void* ptr) {
+    return _mm256_loadu_si256(reinterpret_cast<const __m256i*>(ptr));
+  }
+  void store(void* ptr) const {
+    _mm256_storeu_si256(reinterpret_cast<__m256i*>(ptr), values);
+  }
+
+  Vectorized operator<(const Vectorized& other) const {
+    __m256i max = _mm256_max_epu8(values, other);
+    return invert(_mm256_cmpeq_epi8(max, values));
+  }
+  Vectorized operator-(const Vectorized& b) {
+    return _mm256_sub_epi8(values, b);
+  }
+};
+
+std::ostream& operator<<(std::ostream& stream, const Vectorized& vec) {
+  uint8_t buf[Vectorized::size()];
+  vec.store(buf);
+  stream << "vec[";
+  for (int i = 0; i != Vectorized::size(); i++) {
+    if (i != 0)
+      stream << ", ";
+    stream << buf[i]*1;
+  }
+  stream << "]";
+  return stream;
+}
+
+void run(TensorIteratorBase iter){
+  Vectorized zero_vec(0);
+  Vectorized one_vec(1);
+
+  iter.for_each([=](char* out, char* in, int64_t size) {
+    for (int64_t i = 0; i <= size - Vectorized::size(); i += Vectorized::size()) {
+      auto self_vec = Vectorized::loadu(in + i);
+      auto left = Vectorized::blendv(zero_vec, one_vec, zero_vec < self_vec);
+      auto right = Vectorized::blendv(zero_vec, one_vec, self_vec < zero_vec);
+      auto outv = left - right;
+      outv.store(out + i);
+    }
+  });
+}
+
+void
+test_256 (){
+  char in[32];
+  char out[32];
+  for(auto& x: in) x = 1;
+  run(TensorIteratorBase{in, out});
+  Vectorized::loadu (out);
+  for (int i = 0; i != 32; i++)
+    if (out[i] != 1)
+      __builtin_abort ();
+}
+
+void
+test_128 ()
+{
+}