diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp --- a/llvm/lib/Target/X86/X86InstrInfo.cpp +++ b/llvm/lib/Target/X86/X86InstrInfo.cpp @@ -971,18 +971,19 @@ MachineInstr **AndInstr, const TargetRegisterInfo *TRI, bool &NoSignFlag, bool &ClearsOverflowFlag) { - if (CmpValDefInstr.getOpcode() != X86::SUBREG_TO_REG) + if (!(CmpValDefInstr.getOpcode() == X86::SUBREG_TO_REG && + CmpInstr.getOpcode() == X86::TEST64rr) && + !(CmpValDefInstr.getOpcode() == X86::COPY && + CmpInstr.getOpcode() == X86::TEST16rr)) return false; - if (CmpInstr.getOpcode() != X86::TEST64rr) - return false; - - // CmpInstr is a TEST64rr instruction, and `X86InstrInfo::analyzeCompare` - // guarantees that it's analyzable only if two registers are identical. - assert( - (CmpInstr.getOperand(0).getReg() == CmpInstr.getOperand(1).getReg()) && - "CmpInstr is an analyzable TEST64rr, and `X86InstrInfo::analyzeCompare` " - "requires two reg operands are the same."); + // CmpInstr is a TEST16rr/TEST64rr instruction, and + // `X86InstrInfo::analyzeCompare` guarantees that it's analyzable only if two + // registers are identical. + assert((CmpInstr.getOperand(0).getReg() == CmpInstr.getOperand(1).getReg()) && + "CmpInstr is an analyzable TEST16rr/TEST64rr, and " + "`X86InstrInfo::analyzeCompare` requires two reg operands are the" + "same."); // Caller (`X86InstrInfo::optimizeCompareInstr`) guarantees that // `CmpValDefInstr` defines the value that's used by `CmpInstr`; in this case @@ -990,20 +991,37 @@ // redundant. assert( (MRI->getVRegDef(CmpInstr.getOperand(0).getReg()) == &CmpValDefInstr) && - "Caller guarantees that TEST64rr is a user of SUBREG_TO_REG."); + "Caller guarantees that TEST64rr is a user of SUBREG_TO_REG or TEST16rr " + "is a user of COPY sub16bit."); + MachineInstr *VregDefInstr = nullptr; + if (CmpValDefInstr.getOpcode() == X86::COPY && + CmpInstr.getOpcode() == X86::TEST16rr) { + VregDefInstr = MRI->getVRegDef(CmpValDefInstr.getOperand(1).getReg()); + if (!VregDefInstr) + return false; + // We can only remove test when AND32ri or AND64ri32 whose imm can fit 16bit + // size, others 32/64 bit ops would test higher bits which test16rr don't + // want to. + if (!((VregDefInstr->getOpcode() == X86::AND32ri || + VregDefInstr->getOpcode() == X86::AND64ri32) && + isUInt<16>(VregDefInstr->getOperand(2).getImm()))) + return false; + } - // As seen in X86 td files, CmpValDefInstr.getOperand(1).getImm() is typically - // 0. - if (CmpValDefInstr.getOperand(1).getImm() != 0) - return false; + if (CmpValDefInstr.getOpcode() == X86::SUBREG_TO_REG && + CmpInstr.getOpcode() == X86::TEST64rr) { + // As seen in X86 td files, CmpValDefInstr.getOperand(1).getImm() is + // typically 0. + if (CmpValDefInstr.getOperand(1).getImm() != 0) + return false; - // As seen in X86 td files, CmpValDefInstr.getOperand(3) is typically - // sub_32bit or sub_xmm. - if (CmpValDefInstr.getOperand(3).getImm() != X86::sub_32bit) - return false; + // As seen in X86 td files, CmpValDefInstr.getOperand(3) is typically + // sub_32bit or sub_xmm. + if (CmpValDefInstr.getOperand(3).getImm() != X86::sub_32bit) + return false; - MachineInstr *VregDefInstr = - MRI->getVRegDef(CmpValDefInstr.getOperand(2).getReg()); + VregDefInstr = MRI->getVRegDef(CmpValDefInstr.getOperand(2).getReg()); + } assert(VregDefInstr && "Must have a definition (SSA)"); @@ -1021,6 +1039,11 @@ // ... // EFLAGS not changed // %extended_reg = subreg_to_reg 0, %reg, %subreg.sub_32bit // test64rr %extended_reg, %extended_reg, implicit-def $eflags + // or + // %reg = and32* ... + // ... // EFLAGS not changed. + // %src_reg = copy %reg.sub_16bit:gr32 + // test16rr %src_reg, %src_reg, implicit-def $eflags // // If subsequent readers use a subset of bits that don't change // after `and*` instructions, it's likely that the test64rr could @@ -4421,10 +4444,15 @@ break; } - // Look back for the following pattern, in which case the test64rr - // instruction could be erased. + // Look back for the following pattern, in which case the + // test16rr/test64rr instruction could be erased. // - // Example: + // Example for test16rr: + // %reg = and32ri %in_reg, 5 + // ... // EFLAGS not changed. + // %src_reg = copy %reg.sub_16bit:gr32 + // test16rr %src_reg, %src_reg, implicit-def $eflags + // Example for test64rr: // %reg = and32ri %in_reg, 5 // ... // EFLAGS not changed. // %src_reg = subreg_to_reg 0, %reg, %subreg.sub_index diff --git a/llvm/test/CodeGen/X86/peephole-test-after-add.mir b/llvm/test/CodeGen/X86/peephole-test-after-add.mir --- a/llvm/test/CodeGen/X86/peephole-test-after-add.mir +++ b/llvm/test/CodeGen/X86/peephole-test-after-add.mir @@ -58,13 +58,13 @@ entry: %3 = icmp ne i16 %0, 0 %4 = and i32 %1, 123456 - %truc = trunc i32 %4 to i16 - %5 = icmp eq i16 %truc, 0 + %trunc = trunc i32 %4 to i16 + %5 = icmp eq i16 %trunc, 0 %6 = select i1 %3, i1 %5, i1 false br i1 %6, label %if.then, label %if.end if.then: ; preds = %entry - store i16 %0, ptr %2, align 4 + store i32 %4, ptr %2, align 4 br label %if.end if.end: ; preds = %if.then, %entry @@ -303,9 +303,8 @@ ; CHECK-NEXT: bb.1.entry: ; CHECK-NEXT: successors: %bb.2(0x55555555), %bb.3(0x2aaaaaab) ; CHECK-NEXT: {{ $}} - ; CHECK-NEXT: [[AND32ri:%[0-9]+]]:gr32 = AND32ri [[COPY1]], 123, implicit-def dead $eflags + ; CHECK-NEXT: [[AND32ri:%[0-9]+]]:gr32 = AND32ri [[COPY1]], 123, implicit-def $eflags ; CHECK-NEXT: [[COPY4:%[0-9]+]]:gr16 = COPY [[AND32ri]].sub_16bit - ; CHECK-NEXT: TEST16rr [[COPY4]], [[COPY4]], implicit-def $eflags ; CHECK-NEXT: JCC_1 %bb.3, 5, implicit $eflags ; CHECK-NEXT: JMP_1 %bb.2 ; CHECK-NEXT: {{ $}} @@ -374,16 +373,16 @@ registers: - { id: 0, class: gr32, preferred-register: '' } - { id: 1, class: gr32, preferred-register: '' } - - { id: 2, class: gr64, preferred-register: '' } - - { id: 3, class: gr16, preferred-register: '' } + - { id: 2, class: gr32, preferred-register: '' } + - { id: 3, class: gr64, preferred-register: '' } - { id: 4, class: gr16, preferred-register: '' } - - { id: 5, class: gr32, preferred-register: '' } + - { id: 5, class: gr16, preferred-register: '' } - { id: 6, class: gr32, preferred-register: '' } - { id: 7, class: gr16, preferred-register: '' } liveins: - - { reg: '$edi', virtual-reg: '%0' } - - { reg: '$esi', virtual-reg: '%1' } - - { reg: '$rdx', virtual-reg: '%2' } + - { reg: '$edi', virtual-reg: '%1' } + - { reg: '$esi', virtual-reg: '%2' } + - { reg: '$rdx', virtual-reg: '%3' } frameInfo: isFrameAddressTaken: false isReturnAddressTaken: false @@ -429,7 +428,7 @@ ; CHECK-NEXT: bb.1.entry: ; CHECK-NEXT: successors: %bb.2(0x55555555), %bb.3(0x2aaaaaab) ; CHECK-NEXT: {{ $}} - ; CHECK-NEXT: [[AND32ri:%[0-9]+]]:gr32 = AND32ri [[COPY1]], 57920, implicit-def dead $eflags + ; CHECK-NEXT: [[AND32ri:%[0-9]+]]:gr32 = AND32ri [[COPY1]], 123456, implicit-def dead $eflags ; CHECK-NEXT: [[COPY4:%[0-9]+]]:gr16 = COPY [[AND32ri]].sub_16bit ; CHECK-NEXT: TEST16rr [[COPY4]], [[COPY4]], implicit-def $eflags ; CHECK-NEXT: JCC_1 %bb.3, 5, implicit $eflags @@ -438,7 +437,7 @@ ; CHECK-NEXT: bb.2.if.then: ; CHECK-NEXT: successors: %bb.3(0x80000000) ; CHECK-NEXT: {{ $}} - ; CHECK-NEXT: MOV16mr [[COPY]], 1, $noreg, 0, $noreg, [[COPY3]] :: (store (s16) into %ir.2, align 4) + ; CHECK-NEXT: MOV32mr [[COPY]], 1, $noreg, 0, $noreg, [[AND32ri]] :: (store (s32) into %ir.2) ; CHECK-NEXT: {{ $}} ; CHECK-NEXT: bb.3.if.end: ; CHECK-NEXT: [[MOV32r0_:%[0-9]+]]:gr32 = MOV32r0 implicit-def dead $eflags @@ -449,19 +448,19 @@ successors: %bb.3(0x60000000), %bb.2(0x20000000) liveins: $edi, $esi, $rdx - %2:gr64 = COPY $rdx - %1:gr32 = COPY $esi - %0:gr32 = COPY $edi - %3:gr16 = COPY %0.sub_16bit - TEST16rr %3, %3, implicit-def $eflags + %3:gr64 = COPY $rdx + %2:gr32 = COPY $esi + %1:gr32 = COPY $edi + %5:gr16 = COPY %1.sub_16bit + TEST16rr %5, %5, implicit-def $eflags JCC_1 %bb.2, 4, implicit $eflags JMP_1 %bb.3 bb.3.entry: successors: %bb.1(0x55555555), %bb.2(0x2aaaaaab) - %5:gr32 = AND32ri %1, 57920, implicit-def dead $eflags - %4:gr16 = COPY %5.sub_16bit + %0:gr32 = AND32ri %2, 123456, implicit-def dead $eflags + %4:gr16 = COPY %0.sub_16bit TEST16rr %4, %4, implicit-def $eflags JCC_1 %bb.2, 5, implicit $eflags JMP_1 %bb.1 @@ -469,7 +468,7 @@ bb.1.if.then: successors: %bb.2(0x80000000) - MOV16mr %2, 1, $noreg, 0, $noreg, %3 :: (store (s16) into %ir.2, align 4) + MOV32mr %3, 1, $noreg, 0, $noreg, %0 :: (store (s32) into %ir.2) bb.2.if.end: %6:gr32 = MOV32r0 implicit-def dead $eflags