Index: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp =================================================================== --- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp +++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp @@ -6417,18 +6417,30 @@ return false; } +// TODO: There are many more machine instruction opcodes to match: +// 1. Other data types (double, integer, vectors) +// 2. Other math / logic operations (mul, and, or) +static bool isAssociativeAndCommutative(unsigned Opcode) { + switch (Opcode) { + case X86::VADDSSrr: + case X86::ADDSSrr: + return true; + default: + return false; + } +} + /// Return true if the input instruction is part of a chain of dependent ops /// that are suitable for reassociation, otherwise return false. /// If the instruction's operands must be commuted to have a previous /// instruction of the same type define the first source operand, Commuted will /// be set to true. -static bool isReassocCandidate(const MachineInstr &Inst, unsigned AssocOpcode, - bool &Commuted) { - // 1. The instruction must have the correct type. +static bool isReassocCandidate(const MachineInstr &Inst, bool &Commuted) { + // 1. The operation must be associative and commutative. // 2. The instruction must have virtual register definitions for its // operands in the same basic block. - // 3. The instruction must have a reassociatable sibling. - if (Inst.getOpcode() == AssocOpcode && + // 3. The instruction must have a reassociable sibling. + if (isAssociativeAndCommutative(Inst.getOpcode()) && hasVirtualRegDefsInBasicBlock(Inst, Inst.getParent()) && hasReassocSibling(Inst, Commuted)) return true; @@ -6455,14 +6467,8 @@ // B = A op X (Prev) // C = B op Y (Root) - // TODO: There are many more associative instruction types to match: - // 1. Other forms of scalar FP add (non-AVX) - // 2. Other data types (double, integer, vectors) - // 3. Other math / logic operations (mul, and, or) - unsigned AssocOpcode = X86::VADDSSrr; - - bool Commute = false; - if (isReassocCandidate(Root, AssocOpcode, Commute)) { + bool Commute; + if (isReassocCandidate(Root, Commute)) { // We found a sequence of instructions that may be suitable for a // reassociation of operands to increase ILP. Specify each commutation // possibility for the Prev instruction in the sequence and let the Index: llvm/trunk/test/CodeGen/X86/machine-combiner.ll =================================================================== --- llvm/trunk/test/CodeGen/X86/machine-combiner.ll +++ llvm/trunk/test/CodeGen/X86/machine-combiner.ll @@ -1,15 +1,23 @@ -; RUN: llc -mtriple=x86_64-unknown-unknown -mcpu=x86-64 -mattr=avx -enable-unsafe-fp-math < %s | FileCheck %s +; RUN: llc -mtriple=x86_64-unknown-unknown -mcpu=x86-64 -mattr=sse -enable-unsafe-fp-math < %s | FileCheck %s --check-prefix=SSE +; RUN: llc -mtriple=x86_64-unknown-unknown -mcpu=x86-64 -mattr=avx -enable-unsafe-fp-math < %s | FileCheck %s --check-prefix=AVX ; Verify that the first two adds are independent regardless of how the inputs are ; commuted. The destination registers are used as source registers for the third add. define float @reassociate_adds1(float %x0, float %x1, float %x2, float %x3) { -; CHECK-LABEL: reassociate_adds1: -; CHECK: # BB#0: -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds1: +; SSE: # BB#0: +; SSE-NEXT: addss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds1: +; AVX: # BB#0: +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fadd float %x0, %x1 %t1 = fadd float %t0, %x2 %t2 = fadd float %t1, %x3 @@ -17,12 +25,19 @@ } define float @reassociate_adds2(float %x0, float %x1, float %x2, float %x3) { -; CHECK-LABEL: reassociate_adds2: -; CHECK: # BB#0: -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds2: +; SSE: # BB#0: +; SSE-NEXT: addss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds2: +; AVX: # BB#0: +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fadd float %x0, %x1 %t1 = fadd float %x2, %t0 %t2 = fadd float %t1, %x3 @@ -30,12 +45,19 @@ } define float @reassociate_adds3(float %x0, float %x1, float %x2, float %x3) { -; CHECK-LABEL: reassociate_adds3: -; CHECK: # BB#0: -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds3: +; SSE: # BB#0: +; SSE-NEXT: addss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds3: +; AVX: # BB#0: +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fadd float %x0, %x1 %t1 = fadd float %t0, %x2 %t2 = fadd float %x3, %t1 @@ -43,12 +65,19 @@ } define float @reassociate_adds4(float %x0, float %x1, float %x2, float %x3) { -; CHECK-LABEL: reassociate_adds4: -; CHECK: # BB#0: -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds4: +; SSE: # BB#0: +; SSE-NEXT: addss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds4: +; AVX: # BB#0: +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fadd float %x0, %x1 %t1 = fadd float %x2, %t0 %t2 = fadd float %x3, %t1 @@ -59,16 +88,27 @@ ; produced because that would cost more compile time. define float @reassociate_adds5(float %x0, float %x1, float %x2, float %x3, float %x4, float %x5, float %x6, float %x7) { -; CHECK-LABEL: reassociate_adds5: -; CHECK: # BB#0: -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm5, %xmm4, %xmm1 -; CHECK-NEXT: vaddss %xmm6, %xmm1, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm7, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds5: +; SSE: # BB#0: +; SSE-NEXT: addss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: addss %xmm5, %xmm4 +; SSE-NEXT: addss %xmm6, %xmm4 +; SSE-NEXT: addss %xmm4, %xmm0 +; SSE-NEXT: addss %xmm7, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds5: +; AVX: # BB#0: +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm5, %xmm4, %xmm1 +; AVX-NEXT: vaddss %xmm6, %xmm1, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm7, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fadd float %x0, %x1 %t1 = fadd float %t0, %x2 %t2 = fadd float %t1, %x3 @@ -83,14 +123,21 @@ ; Also, we should reassociate such that the result of the high latency division ; is used by the final 'add' rather than reassociating the %x3 operand with the ; division. The latter reassociation would not improve anything. - + define float @reassociate_adds6(float %x0, float %x1, float %x2, float %x3) { -; CHECK-LABEL: reassociate_adds6: -; CHECK: # BB#0: -; CHECK-NEXT: vdivss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: vaddss %xmm3, %xmm2, %xmm1 -; CHECK-NEXT: vaddss %xmm1, %xmm0, %xmm0 -; CHECK-NEXT: retq +; SSE-LABEL: reassociate_adds6: +; SSE: # BB#0: +; SSE-NEXT: divss %xmm1, %xmm0 +; SSE-NEXT: addss %xmm3, %xmm2 +; SSE-NEXT: addss %xmm2, %xmm0 +; SSE-NEXT: retq +; +; AVX-LABEL: reassociate_adds6: +; AVX: # BB#0: +; AVX-NEXT: vdivss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: vaddss %xmm3, %xmm2, %xmm1 +; AVX-NEXT: vaddss %xmm1, %xmm0, %xmm0 +; AVX-NEXT: retq %t0 = fdiv float %x0, %x1 %t1 = fadd float %x2, %t0 %t2 = fadd float %x3, %t1