[XRay] Fix tail call sleds for AArch64 #141403
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@llvm/pr-subscribers-backend-aarch64 Author: Sebastian Kreutzer (sebastiankreutzer) ChangesThis addresses issue #141051. Full diff: https://github.com/llvm/llvm-project/pull/141403.diff 3 Files Affected:
diff --git a/llvm/lib/CodeGen/XRayInstrumentation.cpp b/llvm/lib/CodeGen/XRayInstrumentation.cpp
index dbdb81d1e6b33..cd00e362e16db 100644
--- a/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -296,8 +296,9 @@ bool XRayInstrumentation::run(MachineFunction &MF) {
case Triple::ArchType::riscv64: {
// For the architectures which don't have a single return instruction
InstrumentationOptions op;
- // RISC-V supports patching tail calls.
- op.HandleTailcall = MF.getTarget().getTargetTriple().isRISCV();
+ // AArch64 and RISC-V support patching tail calls.
+ op.HandleTailcall = MF.getTarget().getTargetTriple().isAArch64() ||
+ MF.getTarget().getTargetTriple().isRISCV() ;
op.HandleAllReturns = true;
prependRetWithPatchableExit(MF, TII, op);
break;
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 1a13adc300d2b..21e6fd28d3b71 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -163,6 +163,7 @@ unsigned AArch64InstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
F.getFnAttributeAsParsedInteger("patchable-function-entry", 9) * 4;
break;
case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
+ case TargetOpcode::PATCHABLE_TAIL_CALL:
case TargetOpcode::PATCHABLE_TYPED_EVENT_CALL:
// An XRay sled can be 4 bytes of alignment plus a 32-byte block.
NumBytes = 36;
diff --git a/llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll b/llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll
index 484dca11104ad..a62257e5c9b40 100644
--- a/llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll
+++ b/llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll
@@ -21,8 +21,12 @@ define i32 @callee() nounwind noinline uwtable "function-instrument"="xray-alway
; CHECK-LINUX-LABEL: .Lxray_sleds_start0:
; CHECK-LINUX-NEXT: [[TMP:.Ltmp[0-9]+]]:
; CHECK-LINUX: .xword .Lxray_sled_0-[[TMP]]
+; CHECK-LINUX: .xword
+; CHECK-LINUX-NEXT: .byte 0x00
; CHECK-LINUX: [[TMP:.Ltmp[0-9]+]]:
; CHECK-LINUX-NEXT: .xword .Lxray_sled_1-[[TMP]]
+; CHECK-LINUX: .xword
+; CHECK-LINUX-NEXT: .byte 0x01
; CHECK-LINUX-LABEL: Lxray_sleds_end0:
; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,callee{{$}}
; CHECK-LINUX: .xword .Lxray_sleds_start0
@@ -32,8 +36,12 @@ define i32 @callee() nounwind noinline uwtable "function-instrument"="xray-alway
; CHECK-MACOS-LABEL: lxray_sleds_start0:
; CHECK-MACOS-NEXT: [[TMP:Ltmp[0-9]+]]:
; CHECK-MACOS: .quad Lxray_sled_0-[[TMP]]
+; CHECK-MACOS-NEXT: .quad
+; CHECK-MACOS-NEXT: .byte 0x00
; CHECK-MACOS: [[TMP:Ltmp[0-9]+]]:
; CHECK-MACOS-NEXT: .quad Lxray_sled_1-[[TMP]]
+; CHECK-MACOS-NEXT: .quad
+; CHECK-MACOS-NEXT: .byte 0x01
; CHECK-MACOS-LABEL: Lxray_sleds_end0:
; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
; CHECK-MACOS: [[IDX:lxray_fn_idx[0-9]+]]:
@@ -60,7 +68,11 @@ define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-alway
; CHECK-LINUX-LABEL: .section xray_instr_map,"ao",@progbits,caller{{$}}
; CHECK-LINUX-LABEL: Lxray_sleds_start1:
; CHECK-LINUX: .xword .Lxray_sled_2
+; CHECK-LINUX-NEXT: .xword
+; CHECK-LINUX-NEXT: .byte 0x00
; CHECK-LINUX: .xword .Lxray_sled_3
+; CHECK-LINUX-NEXT: .xword
+; CHECK-LINUX-NEXT: .byte 0x02
; CHECK-LINUX-LABEL: Lxray_sleds_end1:
; CHECK-LINUX-LABEL: .section xray_fn_idx,"ao",@progbits,caller{{$}}
; CHECK-LINUX: [[IDX:\.Lxray_fn_idx[0-9]+]]:
@@ -70,7 +82,11 @@ define i32 @caller() nounwind noinline uwtable "function-instrument"="xray-alway
; CHECK-MACOS-LABEL: .section __DATA,xray_instr_map,regular,live_support{{$}}
; CHECK-MACOS-LABEL: lxray_sleds_start1:
; CHECK-MACOS: .quad Lxray_sled_2
+; CHECK-MACOS-NEXT: .quad
+; CHECK-MACOS-NEXT: .byte 0x00
; CHECK-MACOS: .quad Lxray_sled_3
+; CHECK-MACOS-NEXT: .quad
+; CHECK-MACOS-NEXT: .byte 0x02
; CHECK-MACOS-LABEL: Lxray_sleds_end1:
; CHECK-MACOS-LABEL: .section __DATA,xray_fn_idx,regular,live_support{{$}}
; CHECK-MACOS: [[IDX:lxray_fn_idx[0-9]+]]:
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✅ With the latest revision this PR passed the C/C++ code formatter. |
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As far as I can tell, arm (32bit) and hexagon are affected by the same issue. I will address these targets in a separate PR, once this one goes through. |
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I confirmed this fixed my issue |
MaskRay
approved these changes
May 30, 2025
sivan-shani
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Jun 3, 2025
This addresses issue llvm#141051. XRay uses a special event kind for tail calls on some architectures. This feature is implemented on AArch64, but wasn't fully activated. Tests in `llvm/test/CodeGen/AArch64/xray-tail-call-sled.ll` were incomplete and did not check for the emitted sled type. This patch correctly enables emission of tail call sleds on AArch64 and fixes the tests to check the sled kind.
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This addresses issue #141051.
XRay uses a special event kind for tail calls on some architectures. This feature is implemented on AArch64, but wasn't fully activated.
Tests in
llvm/test/CodeGen/AArch64/xray-tail-call-sled.llwere incomplete and did not check for the emitted sled type.This patch correctly enables emission of tail call sleds on AArch64 and fixes the tests to check the sled kind.