Enable more fold (sext (load x)) -> (sext (truncate (sextload x)))
transformation. Previously, it's restricted by ensuring the number of load uses
is one. Now the restriction is loosened up by allowing setcc uses to be
"extended" (e.g. setcc x, c, eq -> setcc sext(x), sext(c), eq).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43465 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 5decef2..27685a8 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5132,6 +5132,16 @@
return Subtarget->is64Bit() || NumBits1 < 64;
}
+bool X86TargetLowering::isTruncateFree(MVT::ValueType VT1,
+ MVT::ValueType VT2) const {
+ if (!MVT::isInteger(VT1) || !MVT::isInteger(VT2))
+ return false;
+ unsigned NumBits1 = MVT::getSizeInBits(VT1);
+ unsigned NumBits2 = MVT::getSizeInBits(VT2);
+ if (NumBits1 <= NumBits2)
+ return false;
+ return Subtarget->is64Bit() || NumBits1 < 64;
+}
/// isShuffleMaskLegal - Targets can use this to indicate that they only
/// support *some* VECTOR_SHUFFLE operations, those with specific masks.