Introduce new @llvm.get.dynamic.area.offset.i{32, 64} intrinsics.

The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.

Patch by Max Ostapenko.

Differential Revision: http://reviews.llvm.org/D14983

llvm-svn: 254404

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/dyn-alloca-offset.ll b/llvm/test/CodeGen/PowerPC/dyn-alloca-offset.ll
new file mode 100644
index 00000000000..7159b9da736
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/dyn-alloca-offset.ll
@@ -0,0 +1,21 @@
+; RUN: llc -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 < %s | FileCheck %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+declare i64 @llvm.get.dynamic.area.offset.i64()
+
+declare i64 @bar(i64)
+
+attributes #0 = { nounwind }
+
+; Function Attrs: nounwind sanitize_address uwtable
+define signext i64 @foo(i32 signext %N, i32 signext %M) #0 {
+  %1 = alloca i64, align 32
+  %dynamic_area_offset = call i64 @llvm.get.dynamic.area.offset.i64()
+  %2 = call i64 @bar(i64 %dynamic_area_offset)
+  ret i64 %2
+
+; CHECK-DAG: li [[REG1:[0-9]+]], 112
+; CHECK: blr
+
+}