Sink dag combine's post index load / store code that swap base ptr and index into the target hook. Only the target knows whether the swap is safe. In Thumb2 mode, the offset must be an immediate. rdar://7998649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104060 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/test/CodeGen/ARM/2010-05-18-PostIndexBug.ll b/test/CodeGen/ARM/2010-05-18-PostIndexBug.ll
new file mode 100644
index 0000000..9907228
--- /dev/null
+++ b/test/CodeGen/ARM/2010-05-18-PostIndexBug.ll
@@ -0,0 +1,25 @@
+; RUN: llc < %s -mtriple=armv7-apple-darwin   | FileCheck %s -check-prefix=ARM
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin | FileCheck %s -check-prefix=THUMB
+; rdar://7998649
+
+%struct.foo = type { i64, i64 }
+
+define arm_apcscc zeroext i8 @t(%struct.foo* %this) noreturn optsize {
+entry:
+; ARM:       t:
+; ARM:       str r0, [r1], r0
+
+; THUMB:     t:
+; THUMB-NOT: str r0, [r1], r0
+; THUMB:     str r0, [r1]
+  %0 = getelementptr inbounds %struct.foo* %this, i32 0, i32 1 ; <i64*> [#uses=1]
+  store i32 undef, i32* inttoptr (i32 8 to i32*), align 8
+  br i1 undef, label %bb.nph96, label %bb3
+
+bb3:                                              ; preds = %entry
+  %1 = load i64* %0, align 4                      ; <i64> [#uses=0]
+  unreachable
+
+bb.nph96:                                         ; preds = %entry
+  unreachable
+}