[PowerPC] Fix chain for i1-to-fp operation

A simple SELECT is used for converting i1 to floating types on ppc32, but in constrained cases, the chain is not handled properly. This patch will fix that. Reviewed By: steven.zhang Differential Revision: https://reviews.llvm.org/D92365
llvm · Dec 7, 2020 · efdd463 · efdd463
1 parent 216689a
commit efdd463
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Showing 2 changed files with 68 additions and 4 deletions.
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -8718,10 +8718,15 @@ SDValue PPCTargetLowering::LowerINT_TO_FP(SDValue Op,
   if (Op.getValueType() != MVT::f32 && Op.getValueType() != MVT::f64)
     return SDValue();
 
-  if (Src.getValueType() == MVT::i1)
-    return DAG.getNode(ISD::SELECT, dl, Op.getValueType(), Src,
-                       DAG.getConstantFP(1.0, dl, Op.getValueType()),
-                       DAG.getConstantFP(0.0, dl, Op.getValueType()));
+  if (Src.getValueType() == MVT::i1) {
+    SDValue Sel = DAG.getNode(ISD::SELECT, dl, Op.getValueType(), Src,
+                              DAG.getConstantFP(1.0, dl, Op.getValueType()),
+                              DAG.getConstantFP(0.0, dl, Op.getValueType()));
+    if (IsStrict)
+      return DAG.getMergeValues({Sel, Chain}, dl);
+    else
+      return Sel;
+  }
 
   // If we have direct moves, we can do all the conversion, skip the store/load
   // however, without FPCVT we can't do most conversions.

diff --git a/llvm/test/CodeGen/PowerPC/i1-to-fp-chain.ll b/llvm/test/CodeGen/PowerPC/i1-to-fp-chain.ll
@@ -0,0 +1,59 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mtriple=ppc32 < %s | FileCheck %s
+
+@foo = dso_local global double 0.000000e+00, align 8
+
+; Verify the cases won't crash because of missing chains
+
+define double @u1tofp(i1 %i, double %d) #0 {
+; CHECK-LABEL: u1tofp:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    li 4, .LCPI0_0@l
+; CHECK-NEXT:    andi. 3, 3, 1
+; CHECK-NEXT:    addis 3, 4, .LCPI0_0@ha
+; CHECK-NEXT:    li 4, .LCPI0_1@l
+; CHECK-NEXT:    addis 4, 4, .LCPI0_1@ha
+; CHECK-NEXT:    bc 12, 1, .LBB0_1
+; CHECK-NEXT:    b .LBB0_2
+; CHECK-NEXT:  .LBB0_1: # %entry
+; CHECK-NEXT:    addi 3, 4, 0
+; CHECK-NEXT:  .LBB0_2: # %entry
+; CHECK-NEXT:    fmr 0, 1
+; CHECK-NEXT:    lfs 1, 0(3)
+; CHECK-NEXT:    lis 3, foo@ha
+; CHECK-NEXT:    stfd 0, foo@l(3)
+; CHECK-NEXT:    blr
+entry:
+  %conv = tail call double @llvm.experimental.constrained.uitofp.f64.i1(i1 %i, metadata !"round.dynamic", metadata !"fpexcept.strict") #0
+  store volatile double %d, double* @foo, align 8
+  ret double %conv
+}
+
+define double @s1tofp(i1 %i, double %d) #0 {
+; CHECK-LABEL: s1tofp:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    li 4, .LCPI1_0@l
+; CHECK-NEXT:    andi. 3, 3, 1
+; CHECK-NEXT:    addis 3, 4, .LCPI1_0@ha
+; CHECK-NEXT:    li 4, .LCPI1_1@l
+; CHECK-NEXT:    addis 4, 4, .LCPI1_1@ha
+; CHECK-NEXT:    bc 12, 1, .LBB1_1
+; CHECK-NEXT:    b .LBB1_2
+; CHECK-NEXT:  .LBB1_1: # %entry
+; CHECK-NEXT:    addi 3, 4, 0
+; CHECK-NEXT:  .LBB1_2: # %entry
+; CHECK-NEXT:    fmr 0, 1
+; CHECK-NEXT:    lfs 1, 0(3)
+; CHECK-NEXT:    lis 3, foo@ha
+; CHECK-NEXT:    stfd 0, foo@l(3)
+; CHECK-NEXT:    blr
+entry:
+  %conv = tail call double @llvm.experimental.constrained.sitofp.f64.i1(i1 %i, metadata !"round.dynamic", metadata !"fpexcept.strict") #0
+  store volatile double %d, double* @foo, align 8
+  ret double %conv
+}
+
+declare double @llvm.experimental.constrained.uitofp.f64.i1(i1, metadata, metadata)
+declare double @llvm.experimental.constrained.sitofp.f64.i1(i1, metadata, metadata)
+
+attributes #0 = { strictfp }