[llvm] r182499 - This is an update to a previous commit (r181216).
Jean-Luc Duprat
jduprat at apple.com
Wed May 22 11:29:31 PDT 2013
Author: jduprat
Date: Wed May 22 13:29:31 2013
New Revision: 182499
URL: http://llvm.org/viewvc/llvm-project?rev=182499&view=rev
Log:
This is an update to a previous commit (r181216).
The earlier change list introduced the following inst combines:
B * (uitofp i1 C) —> select C, B, 0
A * (1 - uitofp i1 C) —> select C, 0, A
select C, 0, B + select C, A, 0 —> select C, A, B
Together these 3 changes would simplify :
A * (1 - uitofp i1 C) + B * uitofp i1 C
down to :
select C, B, A
In practice we found that the first two substitutions can have a
negative effect on performance, because they reduce opportunities to
use FMA contractions; between the two options FMAs are often the
better choice. This change list amends the previous one to enable
just these inst combines:
select C, B, 0 + select C, 0, A —> select C, B, A
A * (1 - uitofp i1 C) + B * uitofp i1 C —> select C, B, A
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
llvm/trunk/test/Transforms/InstCombine/add4.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp?rev=182499&r1=182498&r2=182499&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp Wed May 22 13:29:31 2013
@@ -1262,6 +1262,49 @@ Instruction *InstCombiner::visitFAdd(Bin
}
}
+ // A * (1 - uitofp i1 C) + B * (uitofp i1 C) -> select C, B, A
+ {
+ if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+ Value *M1L, *M1R, *M2L, *M2R;
+ if (match(LHS, m_FMul(m_Value(M1L), m_Value(M1R))) &&
+ match(RHS, m_FMul(m_Value(M2L), m_Value(M2R)))) {
+
+ Value *A, *B, *C1, *C2;
+ if (!match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))))
+ std::swap(M1L, M1R);
+ if (!match(M2R, m_UIToFp(m_Value(C2))))
+ std::swap(M2L, M2R);
+
+ if (match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))) &&
+ match(M2R, m_UIToFp(m_Value(C2))) &&
+ C2->getType()->isIntegerTy(1) &&
+ C1 == C2) {
+ A = M1L;
+ B = M2L;
+ return SelectInst::Create(C1, B, A);
+ }
+
+ std::swap(M1L, M2L);
+ std::swap(M1R, M2R);
+
+ if (!match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))))
+ std::swap(M1L, M1R);
+ if (!match(M2R, m_UIToFp(m_Value(C2))))
+ std::swap(M2L, M2R);
+
+ if (match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))) &&
+ match(M2R, m_UIToFp(m_Value(C2))) &&
+ C2->getType()->isIntegerTy(1) &&
+ C1 == C2) {
+ A = M1L;
+ B = M2L;
+ return SelectInst::Create(C1, B, A);
+ }
+ }
+ }
+ }
+
+
if (I.hasUnsafeAlgebra()) {
if (Value *V = FAddCombine(Builder).simplify(&I))
return ReplaceInstUsesWith(I, V);
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=182499&r1=182498&r2=182499&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Wed May 22 13:29:31 2013
@@ -524,35 +524,6 @@ Instruction *InstCombiner::visitFMul(Bin
}
}
- // B * (uitofp i1 C) -> select C, B, 0
- if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
- Value *LHS = Op0, *RHS = Op1;
- Value *B, *C;
- if (!match(RHS, m_UIToFp(m_Value(C))))
- std::swap(LHS, RHS);
-
- if (match(RHS, m_UIToFp(m_Value(C))) && C->getType()->isIntegerTy(1)) {
- B = LHS;
- Value *Zero = ConstantFP::getNegativeZero(B->getType());
- return SelectInst::Create(C, B, Zero);
- }
- }
-
- // A * (1 - uitofp i1 C) -> select C, 0, A
- if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
- Value *LHS = Op0, *RHS = Op1;
- Value *A, *C;
- if (!match(RHS, m_FSub(m_FPOne(), m_UIToFp(m_Value(C)))))
- std::swap(LHS, RHS);
-
- if (match(RHS, m_FSub(m_FPOne(), m_UIToFp(m_Value(C)))) &&
- C->getType()->isIntegerTy(1)) {
- A = LHS;
- Value *Zero = ConstantFP::getNegativeZero(A->getType());
- return SelectInst::Create(C, Zero, A);
- }
- }
-
if (!isa<Constant>(Op1))
std::swap(Opnd0, Opnd1);
else
Modified: llvm/trunk/test/Transforms/InstCombine/add4.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/add4.ll?rev=182499&r1=182498&r2=182499&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/add4.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/add4.ll Wed May 22 13:29:31 2013
@@ -6,30 +6,34 @@ target triple = "i686-apple-darwin8"
define float @test1(float %A, float %B, i1 %C) {
EntryBlock:
- ;; A*(1 - uitofp i1 C) -> select C, 0, A
+ ;; select C, 0, B + select C, A, 0 -> select C, A, B
%cf = uitofp i1 %C to float
- %mc = fsub float 1.000000e+00, %cf
- %p1 = fmul fast float %A, %mc
- ret float %p1
+ %s1 = select i1 %C, float 0.000000e+00, float %B
+ %s2 = select i1 %C, float %A, float 0.000000e+00
+ %sum = fadd fast float %s1, %s2
+ ret float %sum
; CHECK: @test1
-; CHECK: select i1 %C, float -0.000000e+00, float %A
+; CHECK: select i1 %C, float %A, float %B
}
define float @test2(float %A, float %B, i1 %C) {
EntryBlock:
- ;; B*(uitofp i1 C) -> select C, B, 0
+ ;; B*(uitofp i1 C) + A*(1 - uitofp i1 C) -> select C, A, B
%cf = uitofp i1 %C to float
+ %mc = fsub fast float 1.000000e+00, %cf
+ %p1 = fmul fast float %A, %mc
%p2 = fmul fast float %B, %cf
- ret float %p2
+ %s1 = fadd fast float %p2, %p1
+ ret float %s1
; CHECK: @test2
-; CHECK: select i1 %C, float %B, float -0.000000e+00
+; CHECK: select i1 %C, float %B, float %A
}
define float @test3(float %A, float %B, i1 %C) {
EntryBlock:
;; A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B
%cf = uitofp i1 %C to float
- %mc = fsub float 1.000000e+00, %cf
+ %mc = fsub fast float 1.000000e+00, %cf
%p1 = fmul fast float %A, %mc
%p2 = fmul fast float %B, %cf
%s1 = fadd fast float %p1, %p2
@@ -38,21 +42,3 @@ EntryBlock:
; CHECK: select i1 %C, float %B, float %A
}
-; PR15952
-define float @test4(float %A, float %B, i32 %C) {
- %cf = uitofp i32 %C to float
- %mc = fsub float 1.000000e+00, %cf
- %p1 = fmul fast float %A, %mc
- ret float %p1
-; CHECK: @test4
-; CHECK: uitofp
-}
-
-define float @test5(float %A, float %B, i32 %C) {
- %cf = uitofp i32 %C to float
- %p2 = fmul fast float %B, %cf
- ret float %p2
-; CHECK: @test5
-; CHECK: uitofp
-}
-
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