[Aarch64] handle "o" inline asm memory constraints
This Linux kernel is making use of this inline asm constraint which is
causing an ICE.
PR49956
Link: https://github.com/ClangBuiltLinux/linux/issues/1348
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D100412
GitOrigin-RevId: bb7016f8f50e1f1b8d388a9a42e3a7bb51254ca2
diff --git a/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp b/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
index f70eee6..3d8aa29 100644
--- a/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ b/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -369,6 +369,7 @@
default:
llvm_unreachable("Unexpected asm memory constraint");
case InlineAsm::Constraint_m:
+ case InlineAsm::Constraint_o:
case InlineAsm::Constraint_Q:
// We need to make sure that this one operand does not end up in XZR, thus
// require the address to be in a PointerRegClass register.
diff --git a/lib/Target/AArch64/AArch64ISelLowering.h b/lib/Target/AArch64/AArch64ISelLowering.h
index 63df223..c67f3b0a 100644
--- a/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/lib/Target/AArch64/AArch64ISelLowering.h
@@ -1027,6 +1027,8 @@
unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
if (ConstraintCode == "Q")
return InlineAsm::Constraint_Q;
+ if (ConstraintCode == "o")
+ return InlineAsm::Constraint_o;
// FIXME: clang has code for 'Ump', 'Utf', 'Usa', and 'Ush' but these are
// followed by llvm_unreachable so we'll leave them unimplemented in
// the backend for now.
diff --git a/test/CodeGen/AArch64/arm64-inline-asm.ll b/test/CodeGen/AArch64/arm64-inline-asm.ll
index 5381e65..cb3e095 100644
--- a/test/CodeGen/AArch64/arm64-inline-asm.ll
+++ b/test/CodeGen/AArch64/arm64-inline-asm.ll
@@ -297,3 +297,13 @@
call void asm sideeffect "", "=*r|m,0,~{memory}"(<9 x float>* nonnull %m.addr, <9 x float> %m)
ret void
}
+
+define void @test_o_output_constraint() {
+; CHECK-LABEL: test_o_output_constraint:
+; CHECK: sub sp, sp, #16
+; CHECK: add x[[REG:[0-9]+]], sp, #15
+; CHECK: mov [x[[REG]]], 7
+ %b = alloca i8, align 1
+ call void asm "mov $0, 7", "=*o"(i8* %b)
+ ret void
+}
