[InstCombine] add tests for extract of vector load; NFC
There's a mismatch internally about how we are handling these patterns.
We count loads as cheapToScalarize(), but then we don't actually
scalarize them, so that can leave extra instructions compared to where
we started when scalarizing other ops. If it's cheapToScalarize, then
we should be scalarizing.
diff --git a/llvm/test/Transforms/InstCombine/scalarization.ll b/llvm/test/Transforms/InstCombine/scalarization.ll
index a5c5600..5865095 100644
--- a/llvm/test/Transforms/InstCombine/scalarization.ll
+++ b/llvm/test/Transforms/InstCombine/scalarization.ll
@@ -1,6 +1,63 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -instcombine -S < %s | FileCheck %s
+define i32 @extract_load(<4 x i32>* %p) {
+; CHECK-LABEL: @extract_load(
+; CHECK-NEXT: [[X:%.*]] = load <4 x i32>, <4 x i32>* [[P:%.*]], align 4
+; CHECK-NEXT: [[EXT:%.*]] = extractelement <4 x i32> [[X]], i32 1
+; CHECK-NEXT: ret i32 [[EXT]]
+;
+ %x = load <4 x i32>, <4 x i32>* %p, align 4
+ %ext = extractelement <4 x i32> %x, i32 1
+ ret i32 %ext
+}
+
+define double @extract_load_fp(<4 x double>* %p) {
+; CHECK-LABEL: @extract_load_fp(
+; CHECK-NEXT: [[X:%.*]] = load <4 x double>, <4 x double>* [[P:%.*]], align 32
+; CHECK-NEXT: [[EXT:%.*]] = extractelement <4 x double> [[X]], i32 3
+; CHECK-NEXT: ret double [[EXT]]
+;
+ %x = load <4 x double>, <4 x double>* %p, align 32
+ %ext = extractelement <4 x double> %x, i32 3
+ ret double %ext
+}
+
+define double @extract_load_volatile(<4 x double>* %p) {
+; CHECK-LABEL: @extract_load_volatile(
+; CHECK-NEXT: [[X:%.*]] = load volatile <4 x double>, <4 x double>* [[P:%.*]], align 32
+; CHECK-NEXT: [[EXT:%.*]] = extractelement <4 x double> [[X]], i32 2
+; CHECK-NEXT: ret double [[EXT]]
+;
+ %x = load volatile <4 x double>, <4 x double>* %p
+ %ext = extractelement <4 x double> %x, i32 2
+ ret double %ext
+}
+
+define double @extract_load_extra_use(<4 x double>* %p, <4 x double>* %p2) {
+; CHECK-LABEL: @extract_load_extra_use(
+; CHECK-NEXT: [[X:%.*]] = load <4 x double>, <4 x double>* [[P:%.*]], align 8
+; CHECK-NEXT: [[EXT:%.*]] = extractelement <4 x double> [[X]], i32 0
+; CHECK-NEXT: store <4 x double> [[X]], <4 x double>* [[P2:%.*]], align 32
+; CHECK-NEXT: ret double [[EXT]]
+;
+ %x = load <4 x double>, <4 x double>* %p, align 8
+ %ext = extractelement <4 x double> %x, i32 0
+ store <4 x double> %x, <4 x double>* %p2
+ ret double %ext
+}
+
+define double @extract_load_variable_index(<4 x double>* %p, i32 %y) {
+; CHECK-LABEL: @extract_load_variable_index(
+; CHECK-NEXT: [[X:%.*]] = load <4 x double>, <4 x double>* [[P:%.*]], align 32
+; CHECK-NEXT: [[EXT:%.*]] = extractelement <4 x double> [[X]], i32 [[Y:%.*]]
+; CHECK-NEXT: ret double [[EXT]]
+;
+ %x = load <4 x double>, <4 x double>* %p
+ %ext = extractelement <4 x double> %x, i32 %y
+ ret double %ext
+}
+
define void @scalarize_phi(i32 * %n, float * %inout) {
; CHECK-LABEL: @scalarize_phi(
; CHECK-NEXT: entry:
