[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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349560 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/scalarization.ll b/test/Transforms/InstCombine/scalarization.ll
index a5c5600f0d29f42932d5128963a3afc73fa7d3a0..586509542b8b82a8944af8785a2cee0049fc76ca 100644 (file)
--- a/test/Transforms/InstCombine/scalarization.ll
+++ b/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: