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
This commit is contained in:
Matt Arsenault 2013-11-04 20:36:06 +00:00
parent da666ab229
commit eba6d38448
3 changed files with 163 additions and 29 deletions

View File

@ -282,6 +282,38 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
Worklist.AddValue(EE);
return CastInst::Create(CI->getOpcode(), EE, EI.getType());
}
} else if (SelectInst *SI = dyn_cast<SelectInst>(I)) {
if (SI->hasOneUse()) {
// TODO: For a select on vectors, it might be useful to do this if it
// has multiple extractelement uses. For vector select, that seems to
// fight the vectorizer.
// If we are extracting an element from a vector select or a select on
// vectors, a select on the scalars extracted from the vector arguments.
Value *TrueVal = SI->getTrueValue();
Value *FalseVal = SI->getFalseValue();
Value *Cond = SI->getCondition();
if (Cond->getType()->isVectorTy()) {
Cond = Builder->CreateExtractElement(Cond,
EI.getIndexOperand(),
Cond->getName() + ".elt");
}
Value *V1Elem
= Builder->CreateExtractElement(TrueVal,
EI.getIndexOperand(),
TrueVal->getName() + ".elt");
Value *V2Elem
= Builder->CreateExtractElement(FalseVal,
EI.getIndexOperand(),
FalseVal->getName() + ".elt");
return SelectInst::Create(Cond,
V1Elem,
V2Elem,
SI->getName() + ".elt");
}
}
}
return 0;

View File

@ -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" }

View File

@ -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: