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-rw-r--r--llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp3
-rw-r--r--llvm/test/CodeGen/AArch64/store_merge_pair_offset.ll12
2 files changed, 15 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index dcb05601e5f..8a76c42b589 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -1470,6 +1470,9 @@ bool AArch64LoadStoreOpt::tryToPairLdStInst(MachineBasicBlock::iterator &MBBI) {
bool IsUnscaled = TII->isUnscaledLdSt(MI);
int Offset = getLdStOffsetOp(MI).getImm();
int OffsetStride = IsUnscaled ? getMemScale(MI) : 1;
+ // Allow one more for offset.
+ if (Offset > 0)
+ Offset -= OffsetStride;
if (!inBoundsForPair(IsUnscaled, Offset, OffsetStride))
return false;
diff --git a/llvm/test/CodeGen/AArch64/store_merge_pair_offset.ll b/llvm/test/CodeGen/AArch64/store_merge_pair_offset.ll
new file mode 100644
index 00000000000..a091f0fd911
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/store_merge_pair_offset.ll
@@ -0,0 +1,12 @@
+; RUN: llc -mtriple=aarch64-linux-gnu -aarch64-enable-atomic-cfg-tidy=0 -disable-lsr -verify-machineinstrs -enable-misched=false -enable-post-misched=false -o - %s | FileCheck %s
+
+define i64 @test(i64* %a) nounwind {
+ ; CHECK: ldp x{{[0-9]+}}, x{{[0-9]+}}
+ ; CHECK-NOT: ldr
+ %p1 = getelementptr inbounds i64, i64* %a, i32 64
+ %tmp1 = load i64, i64* %p1, align 2
+ %p2 = getelementptr inbounds i64, i64* %a, i32 63
+ %tmp2 = load i64, i64* %p2, align 2
+ %tmp3 = add i64 %tmp1, %tmp2
+ ret i64 %tmp3
+}
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