Simplify math a little bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187781 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ce940ad..9925bbb 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -17792,23 +17792,24 @@
// LHS = VECTOR_SHUFFLE A, B, LMask
// RHS = VECTOR_SHUFFLE A, B, RMask
// Check that the masks correspond to performing a horizontal operation.
- for (unsigned i = 0; i != NumElts; ++i) {
- int LIdx = LMask[i], RIdx = RMask[i];
+ for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
+ for (unsigned i = 0; i != NumLaneElts; ++i) {
+ int LIdx = LMask[i+l], RIdx = RMask[i+l];
- // Ignore any UNDEF components.
- if (LIdx < 0 || RIdx < 0 ||
- (!A.getNode() && (LIdx < (int)NumElts || RIdx < (int)NumElts)) ||
- (!B.getNode() && (LIdx >= (int)NumElts || RIdx >= (int)NumElts)))
- continue;
+ // Ignore any UNDEF components.
+ if (LIdx < 0 || RIdx < 0 ||
+ (!A.getNode() && (LIdx < (int)NumElts || RIdx < (int)NumElts)) ||
+ (!B.getNode() && (LIdx >= (int)NumElts || RIdx >= (int)NumElts)))
+ continue;
- // Check that successive elements are being operated on. If not, this is
- // not a horizontal operation.
- unsigned Src = (i/HalfLaneElts) % 2; // each lane is split between srcs
- unsigned LaneStart = (i/NumLaneElts) * NumLaneElts;
- int Index = 2*(i%HalfLaneElts) + NumElts*Src + LaneStart;
- if (!(LIdx == Index && RIdx == Index + 1) &&
- !(IsCommutative && LIdx == Index + 1 && RIdx == Index))
- return false;
+ // Check that successive elements are being operated on. If not, this is
+ // not a horizontal operation.
+ unsigned Src = (i/HalfLaneElts); // each lane is split between srcs
+ int Index = 2*(i%HalfLaneElts) + NumElts*Src + l;
+ if (!(LIdx == Index && RIdx == Index + 1) &&
+ !(IsCommutative && LIdx == Index + 1 && RIdx == Index))
+ return false;
+ }
}
LHS = A.getNode() ? A : B; // If A is 'UNDEF', use B for it.