[MachineOutliner] Keep track of fns that use a redzone in AArch64FunctionInfo

This patch adds a hasRedZone() function to AArch64MachineFunctionInfo. It
returns true if the function is known to use a redzone, false if it is known
to not use a redzone, and no value otherwise.

This removes the requirement to pass -mno-red-zone when outlining for AArch64.

https://reviews.llvm.org/D45189

llvm-svn: 329120

1 files changed, 47 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/AArch64/machine-outliner-noredzone.ll b/llvm/test/CodeGen/AArch64/machine-outliner-noredzone.ll
new file mode 100644
index 00000000000..504f8a8802b
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-noredzone.ll
@@ -0,0 +1,47 @@
+; RUN: llc -enable-machine-outliner %s -o - | FileCheck %s
+; CHECK: OUTLINED_FUNCTION
+; RUN: llc -enable-machine-outliner -aarch64-redzone %s -o - | FileCheck %s -check-prefix=REDZONE
+; REDZONE-NOT: OUTLINED_FUNCTION
+
+target triple = "arm64----"
+
+; Ensure that the MachineOutliner does not fire on functions which use a
+; redzone. foo() should have a redzone when compiled with -aarch64-redzone, and
+; no redzone otherwise.
+define void @foo() #0 {
+  %1 = alloca i32, align 4
+  %2 = alloca i32, align 4
+  %3 = alloca i32, align 4
+  %4 = alloca i32, align 4
+  store i32 0, i32* %1, align 4
+  store i32 0, i32* %2, align 4
+  store i32 0, i32* %3, align 4
+  store i32 0, i32* %4, align 4
+  %5 = load i32, i32* %1, align 4
+  %6 = add nsw i32 %5, 1
+  store i32 %6, i32* %1, align 4
+  %7 = load i32, i32* %3, align 4
+  %8 = add nsw i32 %7, 1
+  store i32 %8, i32* %3, align 4
+  %9 = load i32, i32* %4, align 4
+  %10 = add nsw i32 %9, 1
+  store i32 %10, i32* %4, align 4
+  %11 = load i32, i32* %2, align 4
+  %12 = add nsw i32 %11, 1
+  store i32 %12, i32* %2, align 4
+  %13 = load i32, i32* %1, align 4
+  %14 = add nsw i32 %13, 1
+  store i32 %14, i32* %1, align 4
+  %15 = load i32, i32* %3, align 4
+  %16 = add nsw i32 %15, 1
+  store i32 %16, i32* %3, align 4
+  %17 = load i32, i32* %4, align 4
+  %18 = add nsw i32 %17, 1
+  store i32 %18, i32* %4, align 4
+  %19 = load i32, i32* %2, align 4
+  %20 = add nsw i32 %19, -1
+  store i32 %20, i32* %2, align 4
+  ret void
+}
+
+attributes #0 = { noinline nounwind optnone }