[llvm] 658e476 - [AArch64] Fix wrong condition in `canUseAsPrologue` (#81878)
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Mon Feb 19 02:40:25 PST 2024
Author: Momchil Velikov
Date: 2024-02-19T10:40:21Z
New Revision: 658e4763a23cc53eaf1b84e804f980f2a8cb8802
URL: https://github.com/llvm/llvm-project/commit/658e4763a23cc53eaf1b84e804f980f2a8cb8802
DIFF: https://github.com/llvm/llvm-project/commit/658e4763a23cc53eaf1b84e804f980f2a8cb8802.diff
LOG: [AArch64] Fix wrong condition in `canUseAsPrologue` (#81878)
Inline stack probing code may need a scratch register, hence basic
blocks where such register is not available cannot be used as prologues.
Checking for an available scratch regidster was incorrectly skipped when
the function uses stack probing.
Added:
llvm/test/CodeGen/AArch64/stack-probing-no-scratch-reg.mir
Modified:
llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 8310ddf1d8b398..d98750e09d4e36 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -1063,7 +1063,7 @@ bool AArch64FrameLowering::canUseAsPrologue(
// Don't need a scratch register if we're not going to re-align the stack or
// emit stack probes.
- if (!RegInfo->hasStackRealignment(*MF) && TLI->hasInlineStackProbe(*MF))
+ if (!RegInfo->hasStackRealignment(*MF) && !TLI->hasInlineStackProbe(*MF))
return true;
// Otherwise, we can use any block as long as it has a scratch register
// available.
diff --git a/llvm/test/CodeGen/AArch64/stack-probing-no-scratch-reg.mir b/llvm/test/CodeGen/AArch64/stack-probing-no-scratch-reg.mir
new file mode 100644
index 00000000000000..f50bd9ab4b8a1b
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/stack-probing-no-scratch-reg.mir
@@ -0,0 +1,105 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4
+# RUN: llc %s --start-before=shrink-wrap -stop-after=prologepilog -o - | FileCheck %s
+--- |
+ target triple = "aarch64-linux"
+
+ define void @f(i32 %n) #0 {
+ entry:
+ %a = alloca i8, i32 150000, align 8
+ %c0 = icmp sle i32 %n, 1
+ br i1 %c0, label %if.then1, label %exit
+
+ if.then1:
+ call void @g(ptr %a)
+ br label %exit
+
+ exit:
+ ret void
+ }
+
+ declare void @g(...)
+
+ attributes #0 = { nounwind "probe-stack"="inline-asm" "stack-probe-size"="4096" }
+
+...
+---
+name: f
+alignment: 4
+tracksRegLiveness: true
+liveins:
+ - { reg: '$w0', virtual-reg: '' }
+frameInfo:
+ localFrameSize: 150000
+stack:
+ - { id: 0, name: a, type: default, offset: 0, size: 150000, alignment: 8,
+ stack-id: default, callee-saved-register: '', callee-saved-restored: true,
+ local-offset: -150000, debug-info-variable: '', debug-info-expression: '',
+ debug-info-location: '' }
+entry_values: []
+callSites: []
+debugValueSubstitutions: []
+constants: []
+machineFunctionInfo: {}
+body: |
+ ; CHECK-LABEL: name: f
+ ; CHECK: bb.0.entry:
+ ; CHECK-NEXT: successors: %bb.3(0x80000000)
+ ; CHECK-NEXT: liveins: $w0, $lr
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: early-clobber $sp = frame-setup STPXpre killed $fp, killed $lr, $sp, -2 :: (store (s64) into %stack.2), (store (s64) into %stack.1)
+ ; CHECK-NEXT: $x9 = frame-setup SUBXri $sp, 36, 12
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.3.entry:
+ ; CHECK-NEXT: successors: %bb.4(0x40000000), %bb.3(0x40000000)
+ ; CHECK-NEXT: liveins: $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x9, $x10, $x11, $x12, $x13, $x14, $x15, $x16, $x17, $x18, $x19, $x20, $x21, $x22, $x23, $x25, $x27, $x28
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 1, 12
+ ; CHECK-NEXT: frame-setup STRXui $xzr, $sp, 0
+ ; CHECK-NEXT: $xzr = frame-setup SUBSXrx64 $sp, $x9, 24, implicit-def $nzcv
+ ; CHECK-NEXT: frame-setup Bcc 1, %bb.3, implicit $nzcv
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.4.entry:
+ ; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
+ ; CHECK-NEXT: liveins: $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x10, $x11, $x12, $x13, $x14, $x15, $x16, $x17, $x18, $x19, $x20, $x21, $x22, $x23, $x25, $x27, $x28
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 2544, 0
+ ; CHECK-NEXT: frame-setup STRXui $xzr, $sp, 0
+ ; CHECK-NEXT: $x9 = IMPLICIT_DEF
+ ; CHECK-NEXT: dead $wzr = SUBSWri killed renamable $w0, 1, 0, implicit-def $nzcv
+ ; CHECK-NEXT: Bcc 12, %bb.2, implicit $nzcv
+ ; CHECK-NEXT: B %bb.1
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.1.if.then1:
+ ; CHECK-NEXT: successors: %bb.2(0x80000000)
+ ; CHECK-NEXT: liveins: $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x9, $x10, $x11, $x12, $x13, $x14, $x15, $x16, $x17, $x18, $x19, $x20, $x21, $x22, $x23, $x23, $x25, $x25, $x27, $x28
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: $x0 = ADDXri $sp, 0, 0
+ ; CHECK-NEXT: BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.2.exit:
+ ; CHECK-NEXT: $sp = frame-destroy ADDXri $sp, 36, 12
+ ; CHECK-NEXT: $sp = frame-destroy ADDXri $sp, 2544, 0
+ ; CHECK-NEXT: early-clobber $sp, $fp, $lr = frame-destroy LDPXpost $sp, 2 :: (load (s64) from %stack.2), (load (s64) from %stack.1)
+ ; CHECK-NEXT: RET_ReallyLR
+ bb.0.entry:
+ successors: %bb.1(0x40000000), %bb.2(0x40000000)
+ liveins: $w0
+
+ $x9 = IMPLICIT_DEF
+ dead $wzr = SUBSWri killed renamable $w0, 1, 0, implicit-def $nzcv
+ Bcc 12, %bb.2, implicit $nzcv
+ B %bb.1
+
+ bb.1.if.then1:
+ successors: %bb.2(0x80000000)
+ liveins: $x0, $x1, $x2, $x3, $x4, $x5, $x6, $x7, $x8, $x9, $x10, $x11, $x12, $x13, $x14, $x15, $x16, $x17, $x18, $x19, $x20, $x21, $x22, $x23, $x23, $x25, $x25, $x27, $x28
+
+ ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp
+ $x0 = ADDXri %stack.0.a, 0, 0
+ BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp
+ ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp
+
+ bb.2.exit:
+ RET_ReallyLR
+
+...
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