fix rdar://9297006 - fast isel bails out on trunc to i1 -> bools cry,
a common cause of fast isel rejects on c++ code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129748 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 7be7f18..2c92961 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -865,12 +865,9 @@
unsigned NEReg = createResultReg(&X86::GR8RegClass);
unsigned PReg = createResultReg(&X86::GR8RegClass);
- BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
- TII.get(X86::SETNEr), NEReg);
- BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
- TII.get(X86::SETPr), PReg);
- BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
- TII.get(X86::OR8rr), ResultReg)
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::SETNEr), NEReg);
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::SETPr), PReg);
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::OR8rr),ResultReg)
.addReg(PReg).addReg(NEReg);
UpdateValueMap(I, ResultReg);
return true;
@@ -1068,6 +1065,32 @@
}
}
}
+ } else if (TruncInst *TI = dyn_cast<TruncInst>(BI->getCondition())) {
+ // Handle things like "%cond = trunc i32 %X to i1 / br i1 %cond", which
+ // typically happen for _Bool and C++ bools.
+ MVT SourceVT;
+ if (TI->hasOneUse() && TI->getParent() == I->getParent() &&
+ isTypeLegal(TI->getOperand(0)->getType(), SourceVT)) {
+ unsigned TestOpc = 0;
+ switch (SourceVT.SimpleTy) {
+ default: break;
+ case MVT::i8: TestOpc = X86::TEST8ri; break;
+ case MVT::i16: TestOpc = X86::TEST16ri; break;
+ case MVT::i32: TestOpc = X86::TEST32ri; break;
+ case MVT::i64: TestOpc = X86::TEST64ri32; break;
+ }
+ if (TestOpc) {
+ unsigned OpReg = getRegForValue(TI->getOperand(0));
+ if (OpReg == 0) return false;
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TestOpc))
+ .addReg(OpReg).addImm(1);
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::JNE_4))
+ .addMBB(TrueMBB);
+ FastEmitBranch(FalseMBB, DL);
+ FuncInfo.MBB->addSuccessor(TrueMBB);
+ return true;
+ }
+ }
}
// Otherwise do a clumsy setcc and re-test it.