diff --git a/llvm/lib/Target/AArch64/AArch64BranchTargets.cpp b/llvm/lib/Target/AArch64/AArch64BranchTargets.cpp --- a/llvm/lib/Target/AArch64/AArch64BranchTargets.cpp +++ b/llvm/lib/Target/AArch64/AArch64BranchTargets.cpp @@ -118,6 +118,10 @@ auto MBBI = MBB.begin(); + // Skip the meta instuctions, those will be removed anyway. + for (; MBBI != MBB.end() && MBBI->isMetaInstruction(); ++MBBI) + ; + // PACI[AB]SP are implicitly BTI JC, so no BTI instruction needed there. if (MBBI != MBB.end() && (MBBI->getOpcode() == AArch64::PACIASP || MBBI->getOpcode() == AArch64::PACIBSP)) diff --git a/llvm/test/CodeGen/AArch64/branch-target-enforcement.mir b/llvm/test/CodeGen/AArch64/branch-target-enforcement.mir --- a/llvm/test/CodeGen/AArch64/branch-target-enforcement.mir +++ b/llvm/test/CodeGen/AArch64/branch-target-enforcement.mir @@ -97,6 +97,12 @@ ret i32 %merge2 } + define hidden i32 @debug_ptr_auth() "branch-target-enforcement" { + entry: + tail call void asm sideeffect "", "~{lr}"() + ret i32 0 + } + ... --- # External function, could be addres-taken elsewhere so needs BTI JC. @@ -321,5 +327,30 @@ renamable $x9 = ADDXri killed $x9, target-flags(aarch64-pageoff, aarch64-nc) blockaddress(@label_address, %ir-block.return), 0 STRXui killed renamable $x9, killed renamable $x8, target-flags(aarch64-pageoff, aarch64-nc) @label_address.addr :: (store 8 into @label_address.addr) RET undef $lr, implicit killed $w0 +--- +# When PACIASP is the first real instruction in the functions then BTI should not be inserted. +name: debug_ptr_auth +stack: + - { id: 0, name: '', type: spill-slot, offset: -16, size: 8, alignment: 16, + stack-id: default, callee-saved-register: '$lr', callee-saved-restored: true, + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' } +body: | + bb.0.entry: + liveins: $lr + + ; CHECK-LABEL: name: debug_ptr_auth + ; CHECK-NOT: HINT + ; CHECK: DBG_VALUE + ; CHECK: frame-setup PACIASP + ; CHECK-NOT: HINT + ; CHECK: RETAA + DBG_VALUE $lr + frame-setup PACIASP implicit-def $lr, implicit killed $lr, implicit $sp + frame-setup CFI_INSTRUCTION negate_ra_sign_state + early-clobber $sp = frame-setup STRXpre killed $lr, $sp, -16 :: (store 8 into %stack.0) + INLINEASM &"", 1, 12, implicit-def dead early-clobber $lr + $w0 = ORRWrs $wzr, $wzr, 0 + early-clobber $sp, $lr = frame-destroy LDRXpost $sp, 16 :: (load 8 from %stack.0) + RETAA implicit $sp, implicit $lr, implicit killed $w0 ...