diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp index f13344a27bf8b..029b2ea80cac3 100644 --- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp @@ -1739,10 +1739,22 @@ void AArch64FrameLowering::emitPrologue(MachineFunction &MF, NumBytes = 0; if (RealignmentPadding > 0) { - BuildMI(MBB, MBBI, DL, TII->get(AArch64::ADDXri), AArch64::X15) - .addReg(AArch64::SP) - .addImm(RealignmentPadding) - .addImm(0); + if (RealignmentPadding >= 4096) { + BuildMI(MBB, MBBI, DL, TII->get(AArch64::MOVi64imm)) + .addReg(AArch64::X16, RegState::Define) + .addImm(RealignmentPadding) + .setMIFlags(MachineInstr::FrameSetup); + BuildMI(MBB, MBBI, DL, TII->get(AArch64::ADDXrr), AArch64::X15) + .addReg(AArch64::SP) + .addReg(AArch64::X16, RegState::Kill) + .setMIFlag(MachineInstr::FrameSetup); + } else { + BuildMI(MBB, MBBI, DL, TII->get(AArch64::ADDXri), AArch64::X15) + .addReg(AArch64::SP) + .addImm(RealignmentPadding) + .addImm(0) + .setMIFlag(MachineInstr::FrameSetup); + } uint64_t AndMask = ~(MFI.getMaxAlign().value() - 1); BuildMI(MBB, MBBI, DL, TII->get(AArch64::ANDXri), AArch64::SP) diff --git a/llvm/test/CodeGen/AArch64/win-align-chkstk.ll b/llvm/test/CodeGen/AArch64/win-align-chkstk.ll index 7c1c3dbfaf6dc..5650d78141846 100644 --- a/llvm/test/CodeGen/AArch64/win-align-chkstk.ll +++ b/llvm/test/CodeGen/AArch64/win-align-chkstk.ll @@ -25,3 +25,28 @@ declare dso_local void @other(ptr noundef) ; CHECK-NEXT: sub sp, sp, x15, lsl #4 ; CHECK-NEXT: add x15, sp, #16 ; CHECK-NEXT: and sp, x15, #0xffffffffffffffe0 + +define dso_local void @func2() { +entry: + %buf = alloca [8192 x i8], align 8192 + %arraydecay = getelementptr inbounds [8192 x i8], ptr %buf, i64 0, i64 0 + call void @other(ptr noundef %arraydecay) + ret void +} + +; CHECK-LABEL: func2: +; CHECK-NEXT: .seh_proc func2 +; CHECK-NEXT: // %bb.0: +; CHECK-NEXT: str x28, [sp, #-32]! +; CHECK-NEXT: .seh_save_reg_x x28, 32 +; CHECK-NEXT: stp x29, x30, [sp, #8] +; CHECK-NEXT: .seh_save_fplr 8 +; CHECK-NEXT: add x29, sp, #8 +; CHECK-NEXT: .seh_add_fp 8 +; CHECK-NEXT: .seh_endprologue +; CHECK-NEXT: mov x15, #1533 +; CHECK-NEXT: bl __chkstk +; CHECK-NEXT: sub sp, sp, x15, lsl #4 +; CHECK-NEXT: mov x16, #8176 +; CHECK-NEXT: add x15, sp, x16 +; CHECK-NEXT: and sp, x15, #0xffffffffffffe000