diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h --- a/llvm/include/llvm/CodeGen/SelectionDAG.h +++ b/llvm/include/llvm/CodeGen/SelectionDAG.h @@ -1224,6 +1224,9 @@ SDValue getAddrSpaceCast(const SDLoc &dl, EVT VT, SDValue Ptr, unsigned SrcAS, unsigned DestAS); + /// Return a freeze using the SDLoc of the value operand. + SDValue getFreeze(SDValue V); + /// Return the specified value casted to /// the target's desired shift amount type. SDValue getShiftAmountOperand(EVT LHSTy, SDValue Op); diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -436,6 +436,7 @@ SDValue visitZERO_EXTEND_VECTOR_INREG(SDNode *N); SDValue visitTRUNCATE(SDNode *N); SDValue visitBITCAST(SDNode *N); + SDValue visitFREEZE(SDNode *N); SDValue visitBUILD_PAIR(SDNode *N); SDValue visitFADD(SDNode *N); SDValue visitFSUB(SDNode *N); @@ -1622,6 +1623,7 @@ case ISD::LIFETIME_END: return visitLIFETIME_END(N); case ISD::FP_TO_FP16: return visitFP_TO_FP16(N); case ISD::FP16_TO_FP: return visitFP16_TO_FP(N); + case ISD::FREEZE: return visitFREEZE(N); case ISD::VECREDUCE_FADD: case ISD::VECREDUCE_FMUL: case ISD::VECREDUCE_ADD: @@ -11576,6 +11578,20 @@ return CombineConsecutiveLoads(N, VT); } +SDValue DAGCombiner::visitFREEZE(SDNode *N) { + SDValue N0 = N->getOperand(0); + + // (freeze (freeze x)) -> (freeze x) + if (N0.getOpcode() == ISD::FREEZE) + return N0; + + // If the input is a constant, return it. + if (isa(N0) || isa(N0)) + return N0; + + return SDValue(); +} + /// We know that BV is a build_vector node with Constant, ConstantFP or Undef /// operands. DstEltVT indicates the destination element value type. SDValue DAGCombiner:: diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1927,6 +1927,10 @@ return SDValue(N, 0); } +SDValue SelectionDAG::getFreeze(SDValue V) { + return getNode(ISD::FREEZE, SDLoc(V), V.getValueType(), V); +} + /// getShiftAmountOperand - Return the specified value casted to /// the target's desired shift amount type. SDValue SelectionDAG::getShiftAmountOperand(EVT LHSTy, SDValue Op) { diff --git a/llvm/test/CodeGen/X86/fast-isel-freeze.ll b/llvm/test/CodeGen/X86/fast-isel-freeze.ll --- a/llvm/test/CodeGen/X86/fast-isel-freeze.ll +++ b/llvm/test/CodeGen/X86/fast-isel-freeze.ll @@ -5,8 +5,8 @@ define i32 @freeze(i32 %t) { ; SDAG-LABEL: freeze: ; SDAG: # %bb.0: -; SDAG-NEXT: movl $10, %eax -; SDAG-NEXT: xorl %edi, %eax +; SDAG-NEXT: movl %edi, %eax +; SDAG-NEXT: xorl $10, %eax ; SDAG-NEXT: retq ; ; FAST-LABEL: freeze: diff --git a/llvm/test/CodeGen/X86/freeze-combine.ll b/llvm/test/CodeGen/X86/freeze-combine.ll new file mode 100644 --- /dev/null +++ b/llvm/test/CodeGen/X86/freeze-combine.ll @@ -0,0 +1,24 @@ +; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py +; RUN: llc -stop-after=finalize-isel -mtriple=x86_64-unknown < %s 2>&1 | FileCheck %s +define i32 @const() { + ; CHECK-LABEL: name: const + ; CHECK: bb.0 (%ir-block.0): + ; CHECK: [[MOV32ri:%[0-9]+]]:gr32 = MOV32ri 1 + ; CHECK: $eax = COPY [[MOV32ri]] + ; CHECK: RET 0, $eax + %y = freeze i32 1 + ret i32 %y +} + +define i32 @fold(i32 %x) { + ; CHECK-LABEL: name: fold + ; CHECK: bb.0 (%ir-block.0): + ; CHECK: liveins: $edi + ; CHECK: [[COPY:%[0-9]+]]:gr32 = COPY $edi + ; CHECK: [[COPY1:%[0-9]+]]:gr32 = COPY [[COPY]] + ; CHECK: $eax = COPY [[COPY1]] + ; CHECK: RET 0, $eax + %y = freeze i32 %x + %z = freeze i32 %y + ret i32 %z +} diff --git a/llvm/test/CodeGen/X86/freeze-legalize.ll b/llvm/test/CodeGen/X86/freeze-legalize.ll --- a/llvm/test/CodeGen/X86/freeze-legalize.ll +++ b/llvm/test/CodeGen/X86/freeze-legalize.ll @@ -5,12 +5,8 @@ define i64 @expand(i32 %x) { ; CHECK-LABEL: expand: ; CHECK: ## %bb.0: -; CHECK-NEXT: movl $303174162, %eax ## imm = 0x12121212 -; CHECK-NEXT: movl $875836468, %ecx ## imm = 0x34343434 -; CHECK-NEXT: movl $1448498774, %edx ## imm = 0x56565656 -; CHECK-NEXT: xorl %eax, %edx -; CHECK-NEXT: movl $2021161080, %eax ## imm = 0x78787878 -; CHECK-NEXT: xorl %ecx, %eax +; CHECK-NEXT: movl $1280068684, %eax ## imm = 0x4C4C4C4C +; CHECK-NEXT: movl $1145324612, %edx ## imm = 0x44444444 ; CHECK-NEXT: retl %y1 = freeze i64 1302123111658042420 ; 0x1212121234343434 %y2 = freeze i64 6221254864647256184 ; 0x5656565678787878 @@ -22,29 +18,11 @@ define <2 x i64> @expand_vec(i32 %x) nounwind { ; CHECK-LABEL: expand_vec: ; CHECK: ## %bb.0: -; CHECK-NEXT: pushl %ebx -; CHECK-NEXT: pushl %edi -; CHECK-NEXT: pushl %esi ; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax -; CHECK-NEXT: movl $16843009, %ecx ## imm = 0x1010101 -; CHECK-NEXT: movl $589505315, %edx ## imm = 0x23232323 -; CHECK-NEXT: movl $303174162, %esi ## imm = 0x12121212 -; CHECK-NEXT: movl $875836468, %edi ## imm = 0x34343434 -; CHECK-NEXT: movl $1162167621, %ebx ## imm = 0x45454545 -; CHECK-NEXT: xorl %ecx, %ebx -; CHECK-NEXT: movl $1734829927, %ecx ## imm = 0x67676767 -; CHECK-NEXT: xorl %edx, %ecx -; CHECK-NEXT: movl $1448498774, %edx ## imm = 0x56565656 -; CHECK-NEXT: xorl %esi, %edx -; CHECK-NEXT: movl $2021161080, %esi ## imm = 0x78787878 -; CHECK-NEXT: xorl %edi, %esi -; CHECK-NEXT: movl %ebx, 12(%eax) -; CHECK-NEXT: movl %ecx, 8(%eax) -; CHECK-NEXT: movl %edx, 4(%eax) -; CHECK-NEXT: movl %esi, (%eax) -; CHECK-NEXT: popl %esi -; CHECK-NEXT: popl %edi -; CHECK-NEXT: popl %ebx +; CHECK-NEXT: movl $1145324612, 12(%eax) ## imm = 0x44444444 +; CHECK-NEXT: movl $1145324612, 8(%eax) ## imm = 0x44444444 +; CHECK-NEXT: movl $1145324612, 4(%eax) ## imm = 0x44444444 +; CHECK-NEXT: movl $1280068684, (%eax) ## imm = 0x4C4C4C4C ; CHECK-NEXT: retl $4 ; <0x1212121234343434, 0x101010123232323> %y1 = freeze <2 x i64> @@ -57,10 +35,7 @@ define i10 @promote() { ; CHECK-LABEL: promote: ; CHECK: ## %bb.0: -; CHECK-NEXT: movw $682, %cx ## imm = 0x2AA -; CHECK-NEXT: movw $992, %ax ## imm = 0x3E0 -; CHECK-NEXT: addl %ecx, %eax -; CHECK-NEXT: ## kill: def $ax killed $ax killed $eax +; CHECK-NEXT: movw $650, %ax ## imm = 0x28A ; CHECK-NEXT: retl %a = freeze i10 682 %b = freeze i10 992 @@ -71,14 +46,8 @@ define <2 x i10> @promote_vec() { ; CHECK-LABEL: promote_vec: ; CHECK: ## %bb.0: -; CHECK-NEXT: movw $125, %ax -; CHECK-NEXT: movw $682, %cx ## imm = 0x2AA -; CHECK-NEXT: movw $393, %dx ## imm = 0x189 -; CHECK-NEXT: addl %eax, %edx -; CHECK-NEXT: movw $992, %ax ## imm = 0x3E0 -; CHECK-NEXT: addl %ecx, %eax -; CHECK-NEXT: ## kill: def $ax killed $ax killed $eax -; CHECK-NEXT: ## kill: def $dx killed $dx killed $edx +; CHECK-NEXT: movw $1674, %ax ## imm = 0x68A +; CHECK-NEXT: movw $518, %dx ## imm = 0x206 ; CHECK-NEXT: retl %a = freeze <2 x i10> %b = freeze <2 x i10>