diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/fast-math.ll | 18 |
2 files changed, 13 insertions, 10 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index f3fe09f1cb0..8b355dcd1b2 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1911,6 +1911,11 @@ Instruction *InstCombiner::visitFSub(BinaryOperator &I) { if (match(Op0, m_FSub(m_Specific(Op1), m_Value(X)))) return BinaryOperator::CreateFNegFMF(X, &I); + // Y - (X + Y) --> -X + // Y - (Y + X) --> -X + if (match(Op1, m_c_FAdd(m_Specific(Op0), m_Value(X)))) + return BinaryOperator::CreateFNegFMF(X, &I); + // TODO: This performs reassociative folds for FP ops. Some fraction of the // functionality has been subsumed by simple pattern matching here and in // InstSimplify. We should let a dedicated reassociation pass handle more diff --git a/llvm/test/Transforms/InstCombine/fast-math.ll b/llvm/test/Transforms/InstCombine/fast-math.ll index 8a802105885..98f878a5b18 100644 --- a/llvm/test/Transforms/InstCombine/fast-math.ll +++ b/llvm/test/Transforms/InstCombine/fast-math.ll @@ -269,8 +269,8 @@ define float @fold8_reassoc(float %f1) { define float @fsub_fadd_common_op_fneg(float %x, float %y) { ; CHECK-LABEL: @fsub_fadd_common_op_fneg( -; CHECK-NEXT: [[TMP1:%.*]] = fsub fast float -0.000000e+00, [[X:%.*]] -; CHECK-NEXT: ret float [[TMP1]] +; CHECK-NEXT: [[R:%.*]] = fsub fast float -0.000000e+00, [[X:%.*]] +; CHECK-NEXT: ret float [[R]] ; %a = fadd float %x, %y %r = fsub fast float %y, %a @@ -283,8 +283,8 @@ define float @fsub_fadd_common_op_fneg(float %x, float %y) { define float @fsub_fadd_common_op_fneg_reassoc_nsz(float %x, float %y) { ; CHECK-LABEL: @fsub_fadd_common_op_fneg_reassoc_nsz( -; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float -0.000000e+00, [[X:%.*]] -; CHECK-NEXT: ret float [[TMP1]] +; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz float -0.000000e+00, [[X:%.*]] +; CHECK-NEXT: ret float [[R]] ; %a = fadd float %x, %y %r = fsub reassoc nsz float %y, %a @@ -295,8 +295,7 @@ define float @fsub_fadd_common_op_fneg_reassoc_nsz(float %x, float %y) { define <2 x float> @fsub_fadd_common_op_fneg_vec(<2 x float> %x, <2 x float> %y) { ; CHECK-LABEL: @fsub_fadd_common_op_fneg_vec( -; CHECK-NEXT: [[A:%.*]] = fadd <2 x float> [[X:%.*]], [[Y:%.*]] -; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz <2 x float> [[Y]], [[A]] +; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz <2 x float> <float -0.000000e+00, float -0.000000e+00>, [[X:%.*]] ; CHECK-NEXT: ret <2 x float> [[R]] ; %a = fadd <2 x float> %x, %y @@ -309,8 +308,8 @@ define <2 x float> @fsub_fadd_common_op_fneg_vec(<2 x float> %x, <2 x float> %y) define float @fsub_fadd_common_op_fneg_commute(float %x, float %y) { ; CHECK-LABEL: @fsub_fadd_common_op_fneg_commute( -; CHECK-NEXT: [[TMP1:%.*]] = fsub reassoc nsz float -0.000000e+00, [[X:%.*]] -; CHECK-NEXT: ret float [[TMP1]] +; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz float -0.000000e+00, [[X:%.*]] +; CHECK-NEXT: ret float [[R]] ; %a = fadd float %y, %x %r = fsub reassoc nsz float %y, %a @@ -321,8 +320,7 @@ define float @fsub_fadd_common_op_fneg_commute(float %x, float %y) { define <2 x float> @fsub_fadd_common_op_fneg_commute_vec(<2 x float> %x, <2 x float> %y) { ; CHECK-LABEL: @fsub_fadd_common_op_fneg_commute_vec( -; CHECK-NEXT: [[A:%.*]] = fadd <2 x float> [[Y:%.*]], [[X:%.*]] -; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz <2 x float> [[Y]], [[A]] +; CHECK-NEXT: [[R:%.*]] = fsub reassoc nsz <2 x float> <float -0.000000e+00, float -0.000000e+00>, [[X:%.*]] ; CHECK-NEXT: ret <2 x float> [[R]] ; %a = fadd <2 x float> %y, %x |
