Rewrite fast-isel integer cast handling to handle more cases, and to be simpler and more consistent.
The practical effects here are that x86-64 fast-isel can now handle trunc from i8 to i1, and ARM fast-isel can handle many more constructs involving integers narrower than 32 bits (including loads, stores, and many integer casts).
rdar://9437928 .
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132099 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index dc44512..098fb68 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -111,8 +111,8 @@
// of whether FastISel can handle them.
MVT VT = RealVT.getSimpleVT();
if (!TLI.isTypeLegal(VT)) {
- // Promote MVT::i1 to a legal type though, because it's common and easy.
- if (VT == MVT::i1)
+ // Handle integer promotions, though, because they're common and easy.
+ if (VT == MVT::i1 || VT == MVT::i8 || VT == MVT::i16)
VT = TLI.getTypeToTransformTo(V->getContext(), VT).getSimpleVT();
else
return 0;
@@ -653,21 +653,13 @@
// Unhandled type. Halt "fast" selection and bail.
return false;
- // Check if the destination type is legal. Or as a special case,
- // it may be i1 if we're doing a truncate because that's
- // easy and somewhat common.
+ // Check if the destination type is legal.
if (!TLI.isTypeLegal(DstVT))
- if (DstVT != MVT::i1 || Opcode != ISD::TRUNCATE)
- // Unhandled type. Halt "fast" selection and bail.
- return false;
+ return false;
- // Check if the source operand is legal. Or as a special case,
- // it may be i1 if we're doing zero-extension because that's
- // easy and somewhat common.
+ // Check if the source operand is legal.
if (!TLI.isTypeLegal(SrcVT))
- if (SrcVT != MVT::i1 || Opcode != ISD::ZERO_EXTEND)
- // Unhandled type. Halt "fast" selection and bail.
- return false;
+ return false;
unsigned InputReg = getRegForValue(I->getOperand(0));
if (!InputReg)
@@ -676,18 +668,6 @@
bool InputRegIsKill = hasTrivialKill(I->getOperand(0));
- // If the operand is i1, arrange for the high bits in the register to be zero.
- if (SrcVT == MVT::i1) {
- SrcVT = TLI.getTypeToTransformTo(I->getContext(), SrcVT);
- InputReg = FastEmitZExtFromI1(SrcVT.getSimpleVT(), InputReg, InputRegIsKill);
- if (!InputReg)
- return false;
- InputRegIsKill = true;
- }
- // If the result is i1, truncate to the target's type for i1 first.
- if (DstVT == MVT::i1)
- DstVT = TLI.getTypeToTransformTo(I->getContext(), DstVT);
-
unsigned ResultReg = FastEmit_r(SrcVT.getSimpleVT(),
DstVT.getSimpleVT(),
Opcode,