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authorJakob Stoklund Olesen <stoklund@2pi.dk>2010-07-11 05:16:54 +0000
committerJakob Stoklund Olesen <stoklund@2pi.dk>2010-07-11 05:16:54 +0000
commite7917bb207d5178dfb26066f839e4c295fd3a1eb (patch)
tree3f2633151b1181bb22570da5bc0da0632224103f /lib
parentcbeeae23c31d32b833c9c7c3e8984e4cbcf22f45 (diff)
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Use COPY for fast-isel bitconvert, but don't create cross-class copies.
This doesn't change the behavior of SelectBitcast for X86. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108073 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r--lib/CodeGen/SelectionDAG/FastISel.cpp13
1 files changed, 6 insertions, 7 deletions
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 63413d77cf..3f7e4a5fac 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -671,13 +671,12 @@ bool FastISel::SelectBitCast(const User *I) {
if (SrcVT.getSimpleVT() == DstVT.getSimpleVT()) {
TargetRegisterClass* SrcClass = TLI.getRegClassFor(SrcVT);
TargetRegisterClass* DstClass = TLI.getRegClassFor(DstVT);
- ResultReg = createResultReg(DstClass);
-
- bool InsertedCopy = TII.copyRegToReg(*FuncInfo.MBB, FuncInfo.InsertPt,
- ResultReg, Op0,
- DstClass, SrcClass, DL);
- if (!InsertedCopy)
- ResultReg = 0;
+ // Don't attempt a cross-class copy. It will likely fail.
+ if (SrcClass == DstClass) {
+ ResultReg = createResultReg(DstClass);
+ BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
+ ResultReg).addReg(Op0);
+ }
}
// If the reg-reg copy failed, select a BIT_CONVERT opcode.