ARM Cost Model: Modify the target independent cost model to ask
the target if it supports the different CAST types. We didn't do this
on X86 because of the different register sizes and types, but on ARM
this makes sense.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172245 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BasicTargetTransformInfo.cpp b/lib/CodeGen/BasicTargetTransformInfo.cpp
index 3892cc4..59192f4 100644
--- a/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -241,6 +241,27 @@
std::pair<unsigned, MVT> SrcLT = TLI->getTypeLegalizationCost(Src);
std::pair<unsigned, MVT> DstLT = TLI->getTypeLegalizationCost(Dst);
+ // Check for NOOP conversions.
+ if (SrcLT.first == DstLT.first &&
+ SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
+
+ // Bitcast between types that are legalized to the same type are free.
+ if (Opcode == Instruction::BitCast || Opcode == Instruction::Trunc)
+ return 0;
+ }
+
+ if (Opcode == Instruction::Trunc &&
+ TLI->isTruncateFree(SrcLT.second, DstLT.second))
+ return 0;
+
+ if (Opcode == Instruction::ZExt &&
+ TLI->isZExtFree(SrcLT.second, DstLT.second))
+ return 0;
+
+ // If the cast is marked as legal (or promote) then assume low cost.
+ if (TLI->isOperationLegalOrPromote(ISD, DstLT.second))
+ return 1;
+
// Handle scalar conversions.
if (!Src->isVectorTy() && !Dst->isVectorTy()) {
@@ -248,14 +269,6 @@
if (Opcode == Instruction::BitCast)
return 0;
- if (Opcode == Instruction::Trunc &&
- TLI->isTruncateFree(SrcLT.second, DstLT.second))
- return 0;
-
- if (Opcode == Instruction::ZExt &&
- TLI->isZExtFree(SrcLT.second, DstLT.second))
- return 0;
-
// Just check the op cost. If the operation is legal then assume it costs 1.
if (!TLI->isOperationExpand(ISD, DstLT.second))
return 1;
@@ -271,10 +284,6 @@
if (SrcLT.first == DstLT.first &&
SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
- // Bitcast between types that are legalized to the same type are free.
- if (Opcode == Instruction::BitCast || Opcode == Instruction::Trunc)
- return 0;
-
// Assume that Zext is done using AND.
if (Opcode == Instruction::ZExt)
return 1;