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

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When moving fcti results from float registers to normal registers
through memory, even though MPI was adjusted to account for endianness,
FIPtr was always adjusted for big-endian, which caused loads of wrong
half of a value in little-endian mode.
This commit is contained in:
DanilaZhebryakov 2025-08-20 13:37:14 +03:00 committed by GitHub
parent fea7e6934a
commit 0a3ee7de9c
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2 changed files with 20 additions and 2 deletions
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5
llvm/lib/Target/PowerPC/PPCISelLowering.cpp
View File

@ -8505,10 +8505,11 @@ 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;

17
llvm/test/CodeGen/PowerPC/fp_to_uint_endian.ll Normal file
View File

@ -0,0 +1,17 @@
; RUN: llc < %s -mcpu=440 -mtriple=ppc32le-unknown-unknown | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-LE
; RUN: llc < %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
}