[PowerPC] Skip combining (uint_to_fp x) if x is not simple type

[lkail]

Summary

Current powerpc64le backend hits

Combining: t7: f64 = uint_to_fp t6
llc: llvm-project/llvm/include/llvm/CodeGen/ValueTypes.h:291: llvm::MVT llvm::EVT::getSimpleVT() const: Assertion `isSimple() && "Expected a SimpleValueType!"' failed.

This patch fixes it by skipping combination if t6 is not simple type.
Fixed https://bugs.llvm.org/show_bug.cgi?id=47660.

[steven.zhang]

LGTM with minor nit.

llvm/test/CodeGen/PowerPC/pr47660.ll

38

The test can be further reduced to

entry:
   %conv1 = uitofp i24 %g.coerce to double
   %mul = fmul double 0.000000e+00, %conv1
   %conv2 = fptoui double %mul to i8
   ret i8 %conv2

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

SDValue PPCTargetLowering::combineFPToIntToFP(SDNode *N,
   SelectionDAG &DAG = DCI.DAG;
   SDLoc dl(N);
   SDValue Op(N, 0);
 
   // Don't handle ppc_fp128 here or conversions that are out-of-range capable
   // from the hardware.
   if (Op.getValueType() != MVT::f32 && Op.getValueType() != MVT::f64)
     return SDValue();
+  if (!Op.getOperand(0).getValueType().isSimple())
+    return SDValue();
   if (Op.getOperand(0).getValueType().getSimpleVT() <= MVT(MVT::i1) ||
       Op.getOperand(0).getValueType().getSimpleVT() > MVT(MVT::i64))
     return SDValue();
 
   SDValue FirstOperand(Op.getOperand(0));
   bool SubWordLoad = FirstOperand.getOpcode() == ISD::LOAD &&
     (FirstOperand.getValueType() == MVT::i8 ||
      FirstOperand.getValueType() == MVT::i16);

llvm/test/CodeGen/PowerPC/pr47660.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -ppc-asm-full-reg-names -verify-machineinstrs \
+; RUN:   -mtriple=powerpc64le-linux-gnu < %s | FileCheck \
+; RUN:   -check-prefix=CHECK-LE %s
+; RUN: llc -ppc-asm-full-reg-names -verify-machineinstrs \
+; RUN:   -mtriple=powerpc64-linux-gnu < %s | FileCheck \
+; RUN:   -check-prefix=CHECK-BE %s
+
+define dso_local i24 @_Z1f1c(i24 %g.coerce) local_unnamed_addr #0 {
+; CHECK-LE-LABEL: _Z1f1c:
+; CHECK-LE:       # %bb.0: # %entry
+; CHECK-LE-NEXT:    clrlwi r3, r3, 24
+; CHECK-LE-NEXT:    xxlxor f1, f1, f1
+; CHECK-LE-NEXT:    mtfprwz f0, r3
+; CHECK-LE-NEXT:    xscvuxddp f0, f0
+; CHECK-LE-NEXT:    xsmuldp f0, f0, f1
+; CHECK-LE-NEXT:    xscvdpsxws f0, f0
+; CHECK-LE-NEXT:    mffprwz r3, f0
+; CHECK-LE-NEXT:    clrldi r3, r3, 32
+; CHECK-LE-NEXT:    blr
+;
+; CHECK-BE-LABEL: _Z1f1c:
+; CHECK-BE:       # %bb.0: # %entry
+; CHECK-BE-NEXT:    clrldi r3, r3, 56
+; CHECK-BE-NEXT:    std r3, -16(r1)
+; CHECK-BE-NEXT:    addis r3, r2, .LCPI0_0@toc@ha
+; CHECK-BE-NEXT:    lfd f0, -16(r1)
+; CHECK-BE-NEXT:    lfs f1, .LCPI0_0@toc@l(r3)
+; CHECK-BE-NEXT:    fcfid f0, f0
+; CHECK-BE-NEXT:    fmul f0, f0, f1
+; CHECK-BE-NEXT:    fctiwz f0, f0
+; CHECK-BE-NEXT:    stfd f0, -8(r1)
+; CHECK-BE-NEXT:    lwz r3, -4(r1)
+; CHECK-BE-NEXT:    clrldi r3, r3, 32
+; CHECK-BE-NEXT:    blr
+entry:
+  %0 = and i24 %g.coerce, 255
+  %conv1 = uitofp i24 %0 to double
+  %mul = fmul double 0.000000e+00, %conv1
+  %conv2 = fptoui double %mul to i8
+  %retval.sroa.0.0.insert.ext = zext i8 %conv2 to i24
+  ret i24 %retval.sroa.0.0.insert.ext
+}
+
+attributes #0 = { "use-soft-float"="false" }