[llvm-branch-commits] [llvm] release/20.x: [PowerPC] Use getSignedTargetConstant in SelectOptimalAddrMode. (#127305) (PR #127350)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-powerpc

Author: None (llvmbot)

<details>
<summary>Changes</summary>

Backport 256145b4b0058ae22a1040cd4b7ea44fc49a4ece

Requested by: @<!-- -->topperc

---
Full diff: https://github.com/llvm/llvm-project/pull/127350.diff


2 Files Affected:

- (modified) llvm/lib/Target/PowerPC/PPCISelLowering.cpp (+2-2) 
- (added) llvm/test/CodeGen/PowerPC/pr127298.ll (+13) 


``````````diff
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 4ca328bd9a9ba..21ff6f050817a 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -19050,8 +19050,8 @@ PPC::AddrMode PPCTargetLowering::SelectOptimalAddrMode(const SDNode *Parent,
         int32_t Addr = (int32_t)CNImm;
         // Otherwise, break this down into LIS + Disp.
         Disp = DAG.getSignedTargetConstant((int16_t)Addr, DL, MVT::i32);
-        Base =
-            DAG.getTargetConstant((Addr - (int16_t)Addr) >> 16, DL, MVT::i32);
+        Base = DAG.getSignedTargetConstant((Addr - (int16_t)Addr) >> 16, DL,
+                                           MVT::i32);
         uint32_t LIS = CNType == MVT::i32 ? PPC::LIS : PPC::LIS8;
         Base = SDValue(DAG.getMachineNode(LIS, DL, CNType, Base), 0);
         break;
diff --git a/llvm/test/CodeGen/PowerPC/pr127298.ll b/llvm/test/CodeGen/PowerPC/pr127298.ll
new file mode 100644
index 0000000000000..f7560216ef7d8
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/pr127298.ll
@@ -0,0 +1,13 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=powerpc | FileCheck %s
+
+define void @foo() {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %Entry
+; CHECK-NEXT:    lis 3, -8530
+; CHECK-NEXT:    lbz 3, -16657(3)
+; CHECK-NEXT:    blr
+Entry:
+  %0 = load volatile i8, ptr inttoptr (i32 -559038737 to ptr), align 1
+  ret void
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/127350