From bc7a61b7036044636f9a2c91c916153532a551f8 Mon Sep 17 00:00:00 2001 From: Jonas Paulsson Date: Thu, 10 Dec 2020 18:05:51 -0600 Subject: [PATCH] Revert "[SystemZFrameLowering] Don't overrwrite R1D (backchain) when probing." Temporarily reverted. This reverts commit ea475c77ff9eab1de7d44684c8fb453b39f70081. --- llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp | 52 ++++++++---------- .../CodeGen/SystemZ/stack-clash-dynamic-alloca.ll | 8 +-- .../test/CodeGen/SystemZ/stack-clash-protection.ll | 63 ++++++---------------- 3 files changed, 41 insertions(+), 82 deletions(-) diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp index 0bfab12..57529c8 100644 --- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp +++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp @@ -488,6 +488,15 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF, MFFrame.setStackSize(StackSize); if (StackSize) { + // Determine if we want to store a backchain. + bool StoreBackchain = MF.getFunction().hasFnAttribute("backchain"); + + // If we need backchain, save current stack pointer. R1 is free at this + // point. + if (StoreBackchain) + BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::LGR)) + .addReg(SystemZ::R1D, RegState::Define).addReg(SystemZ::R15D); + // Allocate StackSize bytes. int64_t Delta = -int64_t(StackSize); const unsigned ProbeSize = TLI.getStackProbeSize(MF); @@ -503,23 +512,18 @@ void SystemZFrameLowering::emitPrologue(MachineFunction &MF, .addImm(StackSize); } else { - bool StoreBackchain = MF.getFunction().hasFnAttribute("backchain"); - // If we need backchain, save current stack pointer. R1 is free at - // this point. - if (StoreBackchain) - BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::LGR)) - .addReg(SystemZ::R1D, RegState::Define).addReg(SystemZ::R15D); emitIncrement(MBB, MBBI, DL, SystemZ::R15D, Delta, ZII); buildCFAOffs(MBB, MBBI, DL, SPOffsetFromCFA + Delta, ZII); - if (StoreBackchain) { - // The back chain is stored topmost with packed-stack. - int Offset = usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0; - BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::STG)) - .addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D) - .addImm(Offset).addReg(0); - } } SPOffsetFromCFA += Delta; + + if (StoreBackchain) { + // The back chain is stored topmost with packed-stack. + int Offset = usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0; + BuildMI(MBB, MBBI, DL, ZII->get(SystemZ::STG)) + .addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D) + .addImm(Offset).addReg(0); + } } if (HasFP) { @@ -664,11 +668,6 @@ void SystemZFrameLowering::inlineStackProbe(MachineFunction &MF, .addMemOperand(MMO); }; - bool StoreBackchain = MF.getFunction().hasFnAttribute("backchain"); - if (StoreBackchain) - BuildMI(*MBB, MBBI, DL, ZII->get(SystemZ::LGR)) - .addReg(SystemZ::R1D, RegState::Define).addReg(SystemZ::R15D); - if (NumFullBlocks < 3) { // Emit unrolled probe statements. for (unsigned int i = 0; i < NumFullBlocks; i++) @@ -678,11 +677,10 @@ void SystemZFrameLowering::inlineStackProbe(MachineFunction &MF, uint64_t LoopAlloc = ProbeSize * NumFullBlocks; SPOffsetFromCFA -= LoopAlloc; - // Use R0D to hold the exit value. - BuildMI(*MBB, MBBI, DL, ZII->get(SystemZ::LGR), SystemZ::R0D) + BuildMI(*MBB, MBBI, DL, ZII->get(SystemZ::LGR), SystemZ::R1D) .addReg(SystemZ::R15D); - buildDefCFAReg(*MBB, MBBI, DL, SystemZ::R0D, ZII); - emitIncrement(*MBB, MBBI, DL, SystemZ::R0D, -int64_t(LoopAlloc), ZII); + buildDefCFAReg(*MBB, MBBI, DL, SystemZ::R1D, ZII); + emitIncrement(*MBB, MBBI, DL, SystemZ::R1D, -int64_t(LoopAlloc), ZII); buildCFAOffs(*MBB, MBBI, DL, -int64_t(SystemZMC::CallFrameSize + LoopAlloc), ZII); @@ -695,7 +693,7 @@ void SystemZFrameLowering::inlineStackProbe(MachineFunction &MF, MBB = LoopMBB; allocateAndProbe(*MBB, MBB->end(), ProbeSize, false/*EmitCFI*/); BuildMI(*MBB, MBB->end(), DL, ZII->get(SystemZ::CLGR)) - .addReg(SystemZ::R15D).addReg(SystemZ::R0D); + .addReg(SystemZ::R15D).addReg(SystemZ::R1D); BuildMI(*MBB, MBB->end(), DL, ZII->get(SystemZ::BRC)) .addImm(SystemZ::CCMASK_ICMP).addImm(SystemZ::CCMASK_CMP_GT).addMBB(MBB); @@ -710,14 +708,6 @@ void SystemZFrameLowering::inlineStackProbe(MachineFunction &MF, if (Residual) allocateAndProbe(*MBB, MBBI, Residual, true/*EmitCFI*/); - if (StoreBackchain) { - // The back chain is stored topmost with packed-stack. - int Offset = usePackedStack(MF) ? SystemZMC::CallFrameSize - 8 : 0; - BuildMI(*MBB, MBBI, DL, ZII->get(SystemZ::STG)) - .addReg(SystemZ::R1D, RegState::Kill).addReg(SystemZ::R15D) - .addImm(Offset).addReg(0); - } - StackAllocMI->eraseFromParent(); } diff --git a/llvm/test/CodeGen/SystemZ/stack-clash-dynamic-alloca.ll b/llvm/test/CodeGen/SystemZ/stack-clash-dynamic-alloca.ll index 7b31876..748f441 100644 --- a/llvm/test/CodeGen/SystemZ/stack-clash-dynamic-alloca.ll +++ b/llvm/test/CodeGen/SystemZ/stack-clash-dynamic-alloca.ll @@ -92,14 +92,14 @@ define i32 @fun2(i32 %n) #0 "stack-probe-size"="4" { ; CHECK-NEXT: stmg %r11, %r15, 88(%r15) ; CHECK-NEXT: .cfi_offset %r11, -72 ; CHECK-NEXT: .cfi_offset %r15, -40 -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: aghi %r0, -160 +; CHECK-NEXT: lgr %r1, %r15 +; CHECK-NEXT: .cfi_def_cfa_register %r1 +; CHECK-NEXT: aghi %r1, -160 ; CHECK-NEXT: .cfi_def_cfa_offset 320 ; CHECK-NEXT: .LBB2_1: # =>This Inner Loop Header: Depth=1 ; CHECK-NEXT: aghi %r15, -8 ; CHECK-NEXT: cg %r0, 0(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB2_1 +; CHECK-NEXT: clgrjh %r15, %r1, .LBB2_1 ; CHECK-NEXT: # %bb.2: ; CHECK-NEXT: .cfi_def_cfa_register %r15 ; CHECK-NEXT: lgr %r11, %r15 diff --git a/llvm/test/CodeGen/SystemZ/stack-clash-protection.ll b/llvm/test/CodeGen/SystemZ/stack-clash-protection.ll index b105306..8166af3 100644 --- a/llvm/test/CodeGen/SystemZ/stack-clash-protection.ll +++ b/llvm/test/CodeGen/SystemZ/stack-clash-protection.ll @@ -48,14 +48,14 @@ define i32 @fun1() #0 { define i32 @fun2() #0 { ; CHECK-LABEL: fun2: ; CHECK: # %bb.0: -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: agfi %r0, -69632 +; CHECK-NEXT: lgr %r1, %r15 +; CHECK-NEXT: .cfi_def_cfa_register %r1 +; CHECK-NEXT: agfi %r1, -69632 ; CHECK-NEXT: .cfi_def_cfa_offset 69792 ; CHECK-NEXT: .LBB2_1: # =>This Inner Loop Header: Depth=1 ; CHECK-NEXT: aghi %r15, -4096 ; CHECK-NEXT: cg %r0, 4088(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB2_1 +; CHECK-NEXT: clgrjh %r15, %r1, .LBB2_1 ; CHECK-NEXT: # %bb.2: ; CHECK-NEXT: .cfi_def_cfa_register %r15 ; CHECK-NEXT: aghi %r15, -2544 @@ -81,15 +81,15 @@ define i32 @fun2() #0 { define void @fun3() #0 { ; CHECK-LABEL: fun3: ; CHECK: # %bb.0: # %entry -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: aghi %r0, -28672 +; CHECK-NEXT: lgr %r1, %r15 +; CHECK-NEXT: .cfi_def_cfa_register %r1 +; CHECK-NEXT: aghi %r1, -28672 ; CHECK-NEXT: .cfi_def_cfa_offset 28832 ; CHECK-NEXT: .LBB3_1: # %entry ; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 ; CHECK-NEXT: aghi %r15, -4096 ; CHECK-NEXT: cg %r0, 4088(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB3_1 +; CHECK-NEXT: clgrjh %r15, %r1, .LBB3_1 ; CHECK-NEXT: # %bb.2: # %entry ; CHECK-NEXT: .cfi_def_cfa_register %r15 ; CHECK-NEXT: mvhi 180(%r15), 0 @@ -110,15 +110,15 @@ entry: define void @fun4() #0 "stack-probe-size"="8192" { ; CHECK-LABEL: fun4: ; CHECK: # %bb.0: # %entry -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: aghi %r0, -24576 +; CHECK-NEXT: lgr %r1, %r15 +; CHECK-NEXT: .cfi_def_cfa_register %r1 +; CHECK-NEXT: aghi %r1, -24576 ; CHECK-NEXT: .cfi_def_cfa_offset 24736 ; CHECK-NEXT: .LBB4_1: # %entry ; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 ; CHECK-NEXT: aghi %r15, -8192 ; CHECK-NEXT: cg %r0, 8184(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB4_1 +; CHECK-NEXT: clgrjh %r15, %r1, .LBB4_1 ; CHECK-NEXT: # %bb.2: # %entry ; CHECK-NEXT: .cfi_def_cfa_register %r15 ; CHECK-NEXT: aghi %r15, -7608 @@ -166,15 +166,15 @@ entry: define void @fun6() #0 "stack-probe-size"="5" { ; CHECK-LABEL: fun6: ; CHECK: # %bb.0: # %entry -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: aghi %r0, -4184 +; CHECK-NEXT: lgr %r1, %r15 +; CHECK-NEXT: .cfi_def_cfa_register %r1 +; CHECK-NEXT: aghi %r1, -4184 ; CHECK-NEXT: .cfi_def_cfa_offset 4344 ; CHECK-NEXT: .LBB6_1: # %entry ; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 ; CHECK-NEXT: aghi %r15, -8 ; CHECK-NEXT: cg %r0, 0(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB6_1 +; CHECK-NEXT: clgrjh %r15, %r1, .LBB6_1 ; CHECK-NEXT: # %bb.2: # %entry ; CHECK-NEXT: .cfi_def_cfa_register %r15 ; CHECK-NEXT: mvhi 180(%r15), 0 @@ -237,37 +237,6 @@ define i32 @fun8() #0 { ret i32 %c } -define void @fun9() #0 "backchain" { -; CHECK-LABEL: fun9: -; CHECK: # %bb.0: # %entry -; CHECK-NEXT: lgr %r0, %r15 -; CHECK-NEXT: lgr %r1, %r15 -; CHECK-NEXT: .cfi_def_cfa_register %r0 -; CHECK-NEXT: aghi %r0, -28672 -; CHECK-NEXT: .cfi_def_cfa_offset 28832 -; CHECK-NEXT: .LBB9_1: # %entry -; CHECK-NEXT: # =>This Inner Loop Header: Depth=1 -; CHECK-NEXT: aghi %r15, -4096 -; CHECK-NEXT: cg %r0, 4088(%r15) -; CHECK-NEXT: clgrjh %r15, %r0, .LBB9_1 -; CHECK-NEXT: # %bb.2: # %entry -; CHECK-NEXT: .cfi_def_cfa_register %r15 -; CHECK-NEXT: stg %r1, 0(%r15) -; CHECK-NEXT: mvhi 180(%r15), 0 -; CHECK-NEXT: l %r0, 180(%r15) -; CHECK-NEXT: aghi %r15, 28672 -; CHECK-NEXT: br %r14 -entry: - %stack = alloca [7122 x i32], align 4 - %i = alloca i32, align 4 - %0 = bitcast [7122 x i32]* %stack to i8* - %i.0.i.0..sroa_cast = bitcast i32* %i to i8* - store volatile i32 0, i32* %i, align 4 - %i.0.i.0.6 = load volatile i32, i32* %i, align 4 - ret void -} - - declare i32 @foo() attributes #0 = { "probe-stack"="inline-asm" } -- 2.7.4