AArch64: Safely handle the incoming sret call argument.
This adds a safe interface to the machine independent InputArg struct
for accessing the index of the original (IR-level) argument. When a
non-native return type is lowered, we generate the hidden
machine-level sret argument on-the-fly. Before this fix, we were
representing this argument as OrigArgIndex == 0, which is an outright
lie. In particular this crashed in the AArch64 backend where we
actually try to access the type of the original argument.
Now we use a sentinel value for machine arguments that have no
original argument index. AArch64, ARM, Mips, and PPC now check for this
case before accessing the original argument.
Fixes <rdar://19792160> Null pointer assertion in AArch64TargetLowering
llvm-svn: 229413
diff --git a/llvm/test/CodeGen/AArch64/implicit-sret.ll b/llvm/test/CodeGen/AArch64/implicit-sret.ll
new file mode 100644
index 0000000..264d519
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/implicit-sret.ll
@@ -0,0 +1,13 @@
+; RUN: llc %s -o - -mtriple=arm64-apple-ios7.0 | FileCheck %s
+;
+; Handle implicit sret arguments that are generated on-the-fly during lowering.
+; <rdar://19792160> Null pointer assertion in AArch64TargetLowering
+
+; CHECK-LABEL: big_retval
+; ... str or stp for the first 1024 bits
+; CHECK: strb wzr, [x8, #128]
+; CHECK: ret
+define i1032 @big_retval() {
+entry:
+ ret i1032 0
+}