[X86] Use correct fp immediate types in _mm_set_ss/sd

Avoids implicit sint_to_fp which wasn't occurring on strict fp codegen

Fixes #104848

(cherry picked from commit 6dcce42)

Author: RKSimon

clang/lib/Headers/emmintrin.h

@@ -1771,7 +1771,7 @@ static __inline__ __m128d __DEFAULT_FN_ATTRS _mm_undefined_pd(void) {
 ///    lower 64 bits contain the value of the parameter. The upper 64 bits are
 ///    set to zero.
 static __inline__ __m128d __DEFAULT_FN_ATTRS _mm_set_sd(double __w) {
-  return __extension__(__m128d){__w, 0};
+  return __extension__(__m128d){__w, 0.0};
 }
 
 /// Constructs a 128-bit floating-point vector of [2 x double], with each

clang/lib/Headers/xmmintrin.h

@@ -1910,7 +1910,7 @@ _mm_undefined_ps(void)
 static __inline__ __m128 __DEFAULT_FN_ATTRS
 _mm_set_ss(float __w)
 {
-  return __extension__ (__m128){ __w, 0, 0, 0 };
+  return __extension__ (__m128){ __w, 0.0f, 0.0f, 0.0f };
 }
 
 /// Constructs a 128-bit floating-point vector of [4 x float], with each

clang/test/CodeGen/X86/strictfp_patterns.c

@@ -0,0 +1,26 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 %s -O2 -emit-llvm -o - -triple x86_64-unknown-unknown -ffreestanding -ffp-exception-behavior=maytrap -Wall -Werror | FileCheck %s
+
+#include <immintrin.h>
+
+// PR104848 - ensure the _mm_set_ss/d headers don't implicity promote any integer/fp values.
+
+// CHECK-LABEL: @test_mm_set_ss(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[VECINIT3_I:%.*]] = insertelement <4 x float> <float poison, float 0.000000e+00, float 0.000000e+00, float 0.000000e+00>, float [[NUM:%.*]], i64 0
+// CHECK-NEXT:    ret <4 x float> [[VECINIT3_I]]
+//
+__m128 test_mm_set_ss(float num)
+{
+    return _mm_set_ss(num);
+}
+
+// CHECK-LABEL: @test_mm_set_sd(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[VECINIT1_I:%.*]] = insertelement <2 x double> <double poison, double 0.000000e+00>, double [[NUM:%.*]], i64 0
+// CHECK-NEXT:    ret <2 x double> [[VECINIT1_I]]
+//
+__m128d test_mm_set_sd(double num)
+{
+    return _mm_set_sd(num);
+}