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llvm-project/llvm/test/Transforms/InstCombine/fmul.ll

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1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; RUN: opt -S -instcombine < %s | FileCheck %s
; (-0.0 - X) * C => X * -C
define float @test1(float %x) {
%sub = fsub float -0.000000e+00, %x
%mul = fmul float %sub, 2.0e+1
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test1(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: fmul float %x, -2.000000e+01
}
; (0.0 - X) * C => X * -C
define float @test2(float %x) {
%sub = fsub nsz float 0.000000e+00, %x
%mul = fmul float %sub, 2.0e+1
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test2(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: fmul float %x, -2.000000e+01
}
; (-0.0 - X) * (-0.0 - Y) => X * Y
define float @test3(float %x, float %y) {
%sub1 = fsub float -0.000000e+00, %x
%sub2 = fsub float -0.000000e+00, %y
Fix a bug in InstCombine where we failed to preserve fast math flags when optimizing an FMUL expression. llvm-svn: 199424
2014-01-17 04:59:41 +08:00
%mul = fmul fast float %sub1, %sub2
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test3(
Fix a bug in InstCombine where we failed to preserve fast math flags when optimizing an FMUL expression. llvm-svn: 199424
2014-01-17 04:59:41 +08:00
; CHECK: fmul fast float %x, %y
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
}
; (0.0 - X) * (0.0 - Y) => X * Y
define float @test4(float %x, float %y) {
%sub1 = fsub nsz float 0.000000e+00, %x
%sub2 = fsub nsz float 0.000000e+00, %y
%mul = fmul float %sub1, %sub2
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test4(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: fmul float %x, %y
}
; (-0.0 - X) * Y => -0.0 - (X * Y)
define float @test5(float %x, float %y) {
%sub1 = fsub float -0.000000e+00, %x
%mul = fmul float %sub1, %y
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test5(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: %1 = fmul float %x, %y
; CHECK: %mul = fsub float -0.000000e+00, %1
}
; (0.0 - X) * Y => 0.0 - (X * Y)
define float @test6(float %x, float %y) {
%sub1 = fsub nsz float 0.000000e+00, %x
%mul = fmul float %sub1, %y
ret float %mul
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test6(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: %1 = fmul float %x, %y
; CHECK: %mul = fsub float -0.000000e+00, %1
}
; "(-0.0 - X) * Y => -0.0 - (X * Y)" is disabled if expression "-0.0 - X"
; has multiple uses.
define float @test7(float %x, float %y) {
%sub1 = fsub float -0.000000e+00, %x
%mul = fmul float %sub1, %y
%mul2 = fmul float %mul, %sub1
ret float %mul2
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @test7(
1. Hoist minus sign as high as possible in an attempt to reveal some optimization opportunities (in the enclosing supper-expressions). rule 1. (-0.0 - X ) * Y => -0.0 - (X * Y) if expression "-0.0 - X" has only one reference. rule 2. (0.0 - X ) * Y => -0.0 - (X * Y) if expression "0.0 - X" has only one reference, and the instruction is marked "noSignedZero". 2. Eliminate negation (The compiler was already able to handle these opt if the 0.0s are replaced with -0.0.) rule 3: (0.0 - X) * (0.0 - Y) => X * Y rule 4: (0.0 - X) * C => X * -C if the expr is flagged "noSignedZero". 3. Rule 5: (X*Y) * X => (X*X) * Y if X!=Y and the expression is flagged with "UnsafeAlgebra". The purpose of this transformation is two-fold: a) to form a power expression (of X). b) potentially shorten the critical path: After transformation, the latency of the instruction Y is amortized by the expression of X*X, and therefore Y is in a "less critical" position compared to what it was before the transformation. 4. Remove the InstCombine code about simplifiying "X * select". The reasons are following: a) The "select" is somewhat architecture-dependent, therefore the higher level optimizers are not able to precisely predict if the simplification really yields any performance improvement or not. b) The "select" operator is bit complicate, and tends to obscure optimization opportunities. It is btter to keep it as low as possible in expr tree, and let CodeGen to tackle the optimization. llvm-svn: 172551
2013-01-16 05:09:32 +08:00
; CHECK: fsub float -0.000000e+00, %x
}
Fix a bug in InstCombine where it attempted to cast a Value* to an Instruction* when it was actually a Constant*. There are quite a few other casts to Instruction that might have the same problem, but this is the only one I have a test case for. llvm-svn: 191668
2013-09-30 22:18:35 +08:00
; Don't crash when attempting to cast a constant FMul to an instruction.
define void @test8(i32* %inout) {
entry:
%0 = load i32* %inout, align 4
%conv = uitofp i32 %0 to float
%vecinit = insertelement <4 x float> <float 0.000000e+00, float 0.000000e+00, float 0.000000e+00, float undef>, float %conv, i32 3
%sub = fsub <4 x float> <float -0.000000e+00, float -0.000000e+00, float -0.000000e+00, float -0.000000e+00>, %vecinit
%1 = shufflevector <4 x float> %sub, <4 x float> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
%mul = fmul <4 x float> zeroinitializer, %1
br label %for.cond
for.cond: ; preds = %for.body, %entry
%local_var_7.0 = phi <4 x float> [ %mul, %entry ], [ %2, %for.body ]
br i1 undef, label %for.body, label %for.end
for.body: ; preds = %for.cond
%2 = insertelement <4 x float> %local_var_7.0, float 0.000000e+00, i32 2
br label %for.cond
for.end: ; preds = %for.cond
ret void
}
Teach InstCombine that (fmul X, -1.0) can be simplified to (fneg X), which LLVM expresses as (fsub -0.0, X). llvm-svn: 199420
2014-01-17 04:36:42 +08:00
; X * -1.0 => -0.0 - X
define float @test9(float %x) {
%mul = fmul float %x, -1.0
ret float %mul
; CHECK-LABEL: @test9(
; CHECK-NOT: fmul
; CHECK: fsub
}