[llvm] [PowerPC] fix bug affecting float to int32 conversion on LE PowerPC (PR #150194)

[via llvm-commits]

https://github.com/DanilaZhebryakov updated https://github.com/llvm/llvm-project/pull/150194

>From d3f63c1092227e6b3c95dbeb5968c2b4256a025d Mon Sep 17 00:00:00 2001
From: Danila Zhebryakov <d.zhebryakov at yandex.ru>
Date: Wed, 23 Jul 2025 12:04:17 +0300
Subject: [PATCH] [PowerPC] fix bug affecting float to int32 conversion on some
 PowerPC CPUs

---
 llvm/lib/Target/PowerPC/PPCISelLowering.cpp    |  5 +++--
 llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 459525ed4ee9a..85eeac06f8753 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -8457,10 +8457,11 @@ void PPCTargetLowering::LowerFP_TO_INTForReuse(SDValue Op, ReuseLoadInfo &RLI,
 
   // Result is a load from the stack slot.  If loading 4 bytes, make sure to
   // add in a bias on big endian.
-  if (Op.getValueType() == MVT::i32 && !i32Stack) {
+  if (Op.getValueType() == MVT::i32 && !i32Stack &&
+      !Subtarget.isLittleEndian()) {
     FIPtr = DAG.getNode(ISD::ADD, dl, FIPtr.getValueType(), FIPtr,
                         DAG.getConstant(4, dl, FIPtr.getValueType()));
-    MPI = MPI.getWithOffset(Subtarget.isLittleEndian() ? 0 : 4);
+    MPI = MPI.getWithOffset(4);
   }
 
   RLI.Chain = Chain;
diff --git a/llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll b/llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll
new file mode 100644
index 0000000000000..9a272af8795b8
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll
@@ -0,0 +1,18 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -verify-machineinstrs < %s -mcpu=440 -mtriple=ppc32le-unknown-unknown | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-LE
+; RUN: llc -verify-machineinstrs < %s -mcpu=440 -mtriple=ppc32-unknown-unknown   | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-BE
+
+define i32 @foo(double %a) {
+; CHECK-LABEL: foo:
+; CHECK-DAG:            fctiwz [[FPR_1_i:[0-9]+]], {{[0-9]+}}
+; CHECK-DAG:            stfd [[FPR_1_i]], [[#%u,VAL1_ADDR:]](1)
+; CHECK-LE-DAG:         lwz {{[0-9]+}}, [[#%u,== VAL1_ADDR]](1)
+; CHECK-BE-DAG:         lwz {{[0-9]+}}, [[#%u,== VAL1_ADDR + 4]](1)
+; CHECK-DAG:            fctiwz [[FPR_2:[0-9]+]], {{[0-9]+}}
+; CHECK-DAG:            stfd [[FPR_2]], [[#%u,VAL2_ADDR:]](1)
+; CHECK-LE-DAG:         lwz {{[0-9]+}}, [[#%u,== VAL2_ADDR]](1)
+; CHECK-BE-DAG:         lwz {{[0-9]+}}, [[#%u,== VAL2_ADDR + 4]](1)
+entry:
+        %tmp.1 = fptoui double %a to i32         ; <i32> [#uses=1]
+        ret i32 %tmp.1
+}