Scalarize select vector arguments when extracted.

When the elements are extracted from a select on vectors
or a vector select, do the select on the extracted scalars
from the input if there is only one use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194013 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 131 insertions, 29 deletions

diff --git a/test/Transforms/InstCombine/select-extractelement.ll b/test/Transforms/InstCombine/select-extractelement.ll
new file mode 100644
index 0000000000..e7ea851d92
--- /dev/null
+++ b/test/Transforms/InstCombine/select-extractelement.ll
@@ -0,0 +1,102 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+declare void @v4float_user(<4 x float>) #0
+
+
+
+define float @extract_one_select(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
+; CHECK-LABEL: @extract_one_select(
+; CHECK-NOT: select i1 {{.*}}, <4 x float>
+  %cmp = icmp ne i32 %c, 0
+  %sel = select i1 %cmp, <4 x float> %a, <4 x float> %b
+  %extract = extractelement <4 x float> %sel, i32 2
+  ret float %extract
+}
+
+; Multiple extractelements
+define <2 x float> @extract_two_select(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
+; CHECK-LABEL: @extract_two_select(
+; CHECK: select i1 {{.*}}, <4 x float>
+  %cmp = icmp ne i32 %c, 0
+  %sel = select i1 %cmp, <4 x float> %a, <4 x float> %b
+  %extract1 = extractelement <4 x float> %sel, i32 1
+  %extract2 = extractelement <4 x float> %sel, i32 2
+  %build1 = insertelement <2 x float> undef, float %extract1, i32 0
+  %build2 = insertelement <2 x float> %build1, float %extract2, i32 1
+  ret <2 x float> %build2
+}
+
+; Select has an extra non-extractelement user, don't change it
+define float @extract_one_select_user(<4 x float> %a, <4 x float> %b, i32 %c) #0 {
+; CHECK-LABEL: @extract_one_select_user(
+; CHECK: select i1 {{.*}}, <4 x float>
+  %cmp = icmp ne i32 %c, 0
+  %sel = select i1 %cmp, <4 x float> %a, <4 x float> %b
+  %extract = extractelement <4 x float> %sel, i32 2
+  call void @v4float_user(<4 x float> %sel)
+  ret float %extract
+}
+
+define float @extract_one_vselect_user(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
+; CHECK-LABEL: @extract_one_vselect_user(
+; CHECK: select <4 x i1> {{.*}}, <4 x float>
+  %cmp = icmp ne <4 x i32> %c, zeroinitializer
+  %sel = select <4 x i1> %cmp, <4 x float> %a, <4 x float> %b
+  %extract = extractelement <4 x float> %sel, i32 2
+  call void @v4float_user(<4 x float> %sel)
+  ret float %extract
+}
+
+; Extract from a vector select
+define float @extract_one_vselect(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
+; CHECK-LABEL: @extract_one_vselect(
+; CHECK-NOT: select <4 x i1>
+  %cmp = icmp ne <4 x i32> %c, zeroinitializer
+  %select = select <4 x i1> %cmp, <4 x float> %a, <4 x float> %b
+  %extract = extractelement <4 x float> %select, i32 0
+  ret float %extract
+}
+
+; Multiple extractelements from a vector select
+define <2 x float> @extract_two_vselect(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
+; CHECK-LABEL: @extract_two_vselect(
+; CHECK-NOT: select i1 {{.*}}, <4 x float>
+  %cmp = icmp ne <4 x i32> %c, zeroinitializer
+  %sel = select <4 x i1> %cmp, <4 x float> %a, <4 x float> %b
+  %extract1 = extractelement <4 x float> %sel, i32 1
+  %extract2 = extractelement <4 x float> %sel, i32 2
+  %build1 = insertelement <2 x float> undef, float %extract1, i32 0
+  %build2 = insertelement <2 x float> %build1, float %extract2, i32 1
+  ret <2 x float> %build2
+}
+
+; All the vector selects should be decomposed into scalar selects
+; Test multiple extractelements
+define <4 x float> @simple_vector_select(<4 x float> %a, <4 x float> %b, <4 x i32> %c) #0 {
+; CHECK-LABEL: @simple_vector_select(
+; CHECK-NOT: select i1 {{.*}}, <4 x float>
+entry:
+  %0 = extractelement <4 x i32> %c, i32 0
+  %tobool = icmp ne i32 %0, 0
+  %a.sink = select i1 %tobool, <4 x float> %a, <4 x float> %b
+  %1 = extractelement <4 x float> %a.sink, i32 0
+  %2 = insertelement <4 x float> undef, float %1, i32 0
+  %3 = extractelement <4 x i32> %c, i32 1
+  %tobool1 = icmp ne i32 %3, 0
+  %a.sink1 = select i1 %tobool1, <4 x float> %a, <4 x float> %b
+  %4 = extractelement <4 x float> %a.sink1, i32 1
+  %5 = insertelement <4 x float> %2, float %4, i32 1
+  %6 = extractelement <4 x i32> %c, i32 2
+  %tobool6 = icmp ne i32 %6, 0
+  %a.sink2 = select i1 %tobool6, <4 x float> %a, <4 x float> %b
+  %7 = extractelement <4 x float> %a.sink2, i32 2
+  %8 = insertelement <4 x float> %5, float %7, i32 2
+  %9 = extractelement <4 x i32> %c, i32 3
+  %tobool11 = icmp ne i32 %9, 0
+  %a.sink3 = select i1 %tobool11, <4 x float> %a, <4 x float> %b
+  %10 = extractelement <4 x float> %a.sink3, i32 3
+  %11 = insertelement <4 x float> %8, float %10, i32 3
+  ret <4 x float> %11
+}
+
+attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
diff --git a/test/Transforms/LoopVectorize/minmax_reduction.ll b/test/Transforms/LoopVectorize/minmax_reduction.ll
index 22dd783393..0e47260984 100644
--- a/test/Transforms/LoopVectorize/minmax_reduction.ll
+++ b/test/Transforms/LoopVectorize/minmax_reduction.ll
@@ -17,7 +17,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp sgt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @max_red(i32 %max) {
 entry:
@@ -46,7 +46,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp sgt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @max_red_inverse_select(i32 %max) {
 entry:
@@ -74,7 +74,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp slt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @min_red(i32 %max) {
 entry:
@@ -103,7 +103,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp slt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @min_red_inverse_select(i32 %max) {
 entry:
@@ -133,7 +133,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ugt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @umax_red(i32 %max) {
 entry:
@@ -162,7 +162,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ugt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @umax_red_inverse_select(i32 %max) {
 entry:
@@ -190,7 +190,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ult <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @umin_red(i32 %max) {
 entry:
@@ -219,7 +219,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ult <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @umin_red_inverse_select(i32 %max) {
 entry:
@@ -248,7 +248,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp slt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @sge_min_red(i32 %max) {
 entry:
@@ -277,7 +277,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp sgt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @sle_min_red(i32 %max) {
 entry:
@@ -306,7 +306,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ult <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @uge_min_red(i32 %max) {
 entry:
@@ -335,7 +335,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: icmp ugt <2 x i32>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define i32 @ule_min_red(i32 %max) {
 entry:
@@ -416,7 +416,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @max_red_float(float %max) #0 {
 entry:
@@ -442,7 +442,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @max_red_float_ge(float %max) #0 {
 entry:
@@ -468,7 +468,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_max_red_float(float %max) #0 {
 entry:
@@ -494,7 +494,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_max_red_float_le(float %max) #0 {
 entry:
@@ -520,7 +520,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @unordered_max_red_float(float %max) #0 {
 entry:
@@ -546,7 +546,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @unordered_max_red_float_ge(float %max) #0 {
 entry:
@@ -572,7 +572,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_unordered_max_red_float(float %max) #0 {
 entry:
@@ -598,7 +598,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp ogt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_unordered_max_red_float_le(float %max) #0 {
 entry:
@@ -627,7 +627,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @min_red_float(float %min) #0 {
 entry:
@@ -653,7 +653,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @min_red_float_le(float %min) #0 {
 entry:
@@ -679,7 +679,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_min_red_float(float %min) #0 {
 entry:
@@ -705,7 +705,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_min_red_float_ge(float %min) #0 {
 entry:
@@ -731,7 +731,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @unordered_min_red_float(float %min) #0 {
 entry:
@@ -757,7 +757,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @unordered_min_red_float_le(float %min) #0 {
 entry:
@@ -783,7 +783,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_unordered_min_red_float(float %min) #0 {
 entry:
@@ -809,7 +809,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x float>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define float @inverted_unordered_min_red_float_ge(float %min) #0 {
 entry:
@@ -836,7 +836,7 @@ for.end:
 ; CHECK: select <2 x i1>
 ; CHECK: middle.block
 ; CHECK: fcmp olt <2 x double>
-; CHECK: select <2 x i1>
+; CHECK: select i1
 
 define double @min_red_double(double %min) #0 {
 entry: