https://github.com/CSharperMantle created https://github.com/llvm/llvm-project/pull/202882
Backport 589faedadf141e5e63f7a1e92a0327fc9bdc9b09 to release/22.x. Supersedes #202821. >From cee06e47014e8d74bd7918229a3f65c5c97b84d3 Mon Sep 17 00:00:00 2001 From: "Rong \"Mantle\" Bao" <[email protected]> Date: Fri, 8 May 2026 08:14:18 +0800 Subject: [PATCH] Inline stack probes immediately after `allocateStack` in `eliminateCallFramePseudoInstr` (#195456) [ Upstream commit 589faedadf141e5e63f7a1e92a0327fc9bdc9b09 ] Revert `bltu` in probing loops to `blt` because commit f162be248636046a20e71209e139347e084b637a isn't applied on release/22.x yet. Link: https://github.com/llvm/llvm-project/pull/192485 ("[RISCV] Use unsigned comparison for stack clash probing loop") --- This PR adds a call to `inlineStackProbe` immediately after `allocateStack` in `eliminateCallFramePseudoInstr`. This allows code generation for stack probe pseudoinstructions in non-entry BBs. Fixes #195454. --- llvm/lib/Target/RISCV/RISCVFrameLowering.cpp | 1 + .../RISCV/stack-probing-dynamic-nonentry.ll | 115 ++++++++++++++++++ 2 files changed, 116 insertions(+) create mode 100644 llvm/test/CodeGen/RISCV/stack-probing-dynamic-nonentry.ll diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp index 8246623e8e5aa..20b43538d69c4 100644 --- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp +++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp @@ -1898,6 +1898,7 @@ MachineBasicBlock::iterator RISCVFrameLowering::eliminateCallFramePseudoInstr( needsDwarfCFI(MF) && !hasFP(MF), /*NeedProbe=*/true, ProbeSize, DynAllocation, MachineInstr::NoFlags); + inlineStackProbe(MF, MBB); } else { const RISCVRegisterInfo &RI = *STI.getRegisterInfo(); RI.adjustReg(MBB, MI, DL, SPReg, SPReg, StackOffset::getFixed(Amount), diff --git a/llvm/test/CodeGen/RISCV/stack-probing-dynamic-nonentry.ll b/llvm/test/CodeGen/RISCV/stack-probing-dynamic-nonentry.ll new file mode 100644 index 0000000000000..4c8bb653b4cff --- /dev/null +++ b/llvm/test/CodeGen/RISCV/stack-probing-dynamic-nonentry.ll @@ -0,0 +1,115 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6 +; RUN: llc -mtriple=riscv64 -mattr=+m -O2 < %s | FileCheck %s -check-prefix=RV64 +; RUN: llc -mtriple=riscv32 -mattr=+m -O2 < %s | FileCheck %s -check-prefix=RV32 + +; Test that very large outgoing call frames in functions with variable-sized +; objects get proper stack probing. The outgoing args are large enough to force +; the PROBED_STACKALLOC path, which must be expanded in a non-entry block. + +define void @f(i64 %n) #0 { +; RV64-LABEL: f: +; RV64: # %bb.0: # %entry +; RV64-NEXT: addi sp, sp, -16 +; RV64-NEXT: .cfi_def_cfa_offset 16 +; RV64-NEXT: sd zero, 0(sp) +; RV64-NEXT: sd ra, 8(sp) # 8-byte Folded Spill +; RV64-NEXT: sd s0, 0(sp) # 8-byte Folded Spill +; RV64-NEXT: .cfi_offset ra, -8 +; RV64-NEXT: .cfi_offset s0, -16 +; RV64-NEXT: addi s0, sp, 16 +; RV64-NEXT: .cfi_def_cfa s0, 0 +; RV64-NEXT: slli a0, a0, 2 +; RV64-NEXT: addi a0, a0, 15 +; RV64-NEXT: andi a0, a0, -16 +; RV64-NEXT: sub a0, sp, a0 +; RV64-NEXT: lui a1, 1 +; RV64-NEXT: .LBB0_1: # %entry +; RV64-NEXT: # =>This Inner Loop Header: Depth=1 +; RV64-NEXT: sub sp, sp, a1 +; RV64-NEXT: sd zero, 0(sp) +; RV64-NEXT: blt a0, sp, .LBB0_1 +; RV64-NEXT: # %bb.2: # %entry +; RV64-NEXT: mv sp, a0 +; RV64-NEXT: lui a1, 5 +; RV64-NEXT: sub t1, sp, a1 +; RV64-NEXT: lui t2, 1 +; RV64-NEXT: .LBB0_3: # %entry +; RV64-NEXT: # =>This Inner Loop Header: Depth=1 +; RV64-NEXT: sub sp, sp, t2 +; RV64-NEXT: sd zero, 0(sp) +; RV64-NEXT: bne sp, t1, .LBB0_3 +; RV64-NEXT: # %bb.4: # %entry +; RV64-NEXT: addi sp, sp, -2048 +; RV64-NEXT: addi sp, sp, -1424 +; RV64-NEXT: sd zero, 0(sp) +; RV64-NEXT: call g +; RV64-NEXT: lui a0, 6 +; RV64-NEXT: addi a0, a0, -624 +; RV64-NEXT: add sp, sp, a0 +; RV64-NEXT: addi sp, s0, -16 +; RV64-NEXT: .cfi_def_cfa sp, 16 +; RV64-NEXT: ld ra, 8(sp) # 8-byte Folded Reload +; RV64-NEXT: ld s0, 0(sp) # 8-byte Folded Reload +; RV64-NEXT: .cfi_restore ra +; RV64-NEXT: .cfi_restore s0 +; RV64-NEXT: addi sp, sp, 16 +; RV64-NEXT: .cfi_def_cfa_offset 0 +; RV64-NEXT: ret +; +; RV32-LABEL: f: +; RV32: # %bb.0: # %entry +; RV32-NEXT: addi sp, sp, -16 +; RV32-NEXT: .cfi_def_cfa_offset 16 +; RV32-NEXT: sw zero, 0(sp) +; RV32-NEXT: sw ra, 12(sp) # 4-byte Folded Spill +; RV32-NEXT: sw s0, 8(sp) # 4-byte Folded Spill +; RV32-NEXT: .cfi_offset ra, -4 +; RV32-NEXT: .cfi_offset s0, -8 +; RV32-NEXT: addi s0, sp, 16 +; RV32-NEXT: .cfi_def_cfa s0, 0 +; RV32-NEXT: slli a0, a0, 2 +; RV32-NEXT: addi a0, a0, 15 +; RV32-NEXT: andi a0, a0, -16 +; RV32-NEXT: sub a0, sp, a0 +; RV32-NEXT: lui a1, 1 +; RV32-NEXT: .LBB0_1: # %entry +; RV32-NEXT: # =>This Inner Loop Header: Depth=1 +; RV32-NEXT: sub sp, sp, a1 +; RV32-NEXT: sw zero, 0(sp) +; RV32-NEXT: blt a0, sp, .LBB0_1 +; RV32-NEXT: # %bb.2: # %entry +; RV32-NEXT: mv sp, a0 +; RV32-NEXT: lui a1, 5 +; RV32-NEXT: sub t1, sp, a1 +; RV32-NEXT: lui t2, 1 +; RV32-NEXT: .LBB0_3: # %entry +; RV32-NEXT: # =>This Inner Loop Header: Depth=1 +; RV32-NEXT: sub sp, sp, t2 +; RV32-NEXT: sw zero, 0(sp) +; RV32-NEXT: bne sp, t1, .LBB0_3 +; RV32-NEXT: # %bb.4: # %entry +; RV32-NEXT: addi sp, sp, -2048 +; RV32-NEXT: addi sp, sp, -1456 +; RV32-NEXT: sw zero, 0(sp) +; RV32-NEXT: call g +; RV32-NEXT: lui a0, 6 +; RV32-NEXT: addi a0, a0, -592 +; RV32-NEXT: add sp, sp, a0 +; RV32-NEXT: addi sp, s0, -16 +; RV32-NEXT: .cfi_def_cfa sp, 16 +; RV32-NEXT: lw ra, 12(sp) # 4-byte Folded Reload +; RV32-NEXT: lw s0, 8(sp) # 4-byte Folded Reload +; RV32-NEXT: .cfi_restore ra +; RV32-NEXT: .cfi_restore s0 +; RV32-NEXT: addi sp, sp, 16 +; RV32-NEXT: .cfi_def_cfa_offset 0 +; RV32-NEXT: ret +entry: + %v = alloca i32, i64 %n + call void @g(ptr %v, [3000 x i64] poison) + ret void +} + +declare void @g(ptr, [3000 x i64]) + +attributes #0 = { "probe-stack"="inline-asm" } _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
