Remove unused variable, and unneeded extract element instruction (#103489)

This PR removes an unneeded extract element instruction from codegen,
along with the variable that captured that instruction's return value.

Author: bob80905

clang/test/SemaHLSL/BuiltIns/normalize-errors.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -emit-llvm -disable-llvm-passes -verify -verify-ignore-unexpected
+// RUN: %clang_cc1 -finclude-default-header -triple dxil-pc-shadermodel6.6-library %s -fnative-half-type -disable-llvm-passes -verify -verify-ignore-unexpected
 
 void test_too_few_arg()
 {

llvm/lib/Target/DirectX/DXILIntrinsicExpansion.cpp

@@ -252,7 +252,6 @@ static bool expandNormalizeIntrinsic(CallInst *Orig) {
     return true;
   }
 
-  Value *Elt = Builder.CreateExtractElement(X, (uint64_t)0);
   unsigned XVecSize = XVec->getNumElements();
   Value *DotProduct = nullptr;
   // use the dot intrinsic corresponding to the vector size

llvm/test/CodeGen/DirectX/normalize.ll

@@ -22,7 +22,6 @@ entry:
 
 define noundef <2 x half> @test_normalize_half2(<2 x half> noundef %p0) {
 entry:
-  ; CHECK: extractelement <2 x half> %{{.*}}, i64 0
   ; EXPCHECK: [[doth2:%.*]] = call half @llvm.dx.dot2.v2f16(<2 x half> %{{.*}}, <2 x half> %{{.*}})
   ; DOPCHECK: [[doth2:%.*]] = call half @dx.op.dot2.f16(i32 54, half %{{.*}}, half %{{.*}}, half %{{.*}}, half %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call half @llvm.dx.rsqrt.f16(half [[doth2]])
@@ -37,7 +36,6 @@ entry:
 
 define noundef <3 x half> @test_normalize_half3(<3 x half> noundef %p0) {
 entry:
-  ; CHECK: extractelement <3 x half> %{{.*}}, i64 0
   ; EXPCHECK: [[doth3:%.*]] = call half @llvm.dx.dot3.v3f16(<3 x half> %{{.*}}, <3 x half> %{{.*}})
   ; DOPCHECK: [[doth3:%.*]] = call half @dx.op.dot3.f16(i32 55, half %{{.*}}, half %{{.*}}, half %{{.*}}, half %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call half @llvm.dx.rsqrt.f16(half [[doth3]])
@@ -52,7 +50,6 @@ entry:
 
 define noundef <4 x half> @test_normalize_half4(<4 x half> noundef %p0) {
 entry:
-  ; CHECK: extractelement <4 x half> %{{.*}}, i64 0
   ; EXPCHECK: [[doth4:%.*]] = call half @llvm.dx.dot4.v4f16(<4 x half> %{{.*}}, <4 x half> %{{.*}})
   ; DOPCHECK: [[doth4:%.*]] = call half @dx.op.dot4.f16(i32 56, half %{{.*}}, half %{{.*}}, half %{{.*}}, half %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call half @llvm.dx.rsqrt.f16(half [[doth4]])
@@ -74,7 +71,6 @@ entry:
 
 define noundef <2 x float> @test_normalize_float2(<2 x float> noundef %p0) {
 entry:
-  ; CHECK: extractelement <2 x float> %{{.*}}, i64 0
   ; EXPCHECK: [[dotf2:%.*]] = call float @llvm.dx.dot2.v2f32(<2 x float> %{{.*}}, <2 x float> %{{.*}})
   ; DOPCHECK: [[dotf2:%.*]] = call float @dx.op.dot2.f32(i32 54, float %{{.*}}, float %{{.*}}, float %{{.*}}, float %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call float @llvm.dx.rsqrt.f32(float [[dotf2]])
@@ -89,7 +85,6 @@ entry:
 
 define noundef <3 x float> @test_normalize_float3(<3 x float> noundef %p0) {
 entry:
-  ; CHECK: extractelement <3 x float> %{{.*}}, i64 0
   ; EXPCHECK: [[dotf3:%.*]] = call float @llvm.dx.dot3.v3f32(<3 x float> %{{.*}}, <3 x float> %{{.*}})
   ; DOPCHECK: [[dotf3:%.*]] = call float @dx.op.dot3.f32(i32 55, float %{{.*}}, float %{{.*}}, float %{{.*}}, float %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call float @llvm.dx.rsqrt.f32(float [[dotf3]])
@@ -104,7 +99,6 @@ entry:
 
 define noundef <4 x float> @test_normalize_float4(<4 x float> noundef %p0) {
 entry:
-  ; CHECK: extractelement <4 x float> %{{.*}}, i64 0
   ; EXPCHECK: [[dotf4:%.*]] = call float @llvm.dx.dot4.v4f32(<4 x float> %{{.*}}, <4 x float> %{{.*}})
   ; DOPCHECK: [[dotf4:%.*]] = call float @dx.op.dot4.f32(i32 56, float %{{.*}}, float %{{.*}}, float %{{.*}}, float %{{.*}})
   ; EXPCHECK: [[rsqrt:%.*]] = call float @llvm.dx.rsqrt.f32(float [[dotf4]])