[PATCH][PPC64LE] Correct little-endian usage of vmrgh* and vmrgl*.
Because the PowerPC vmrgh* and vmrgl* instructions have a built-in
big-endian bias, it is necessary to swap their inputs in little-endian
mode when using them to implement a vector shuffle. This was
previously missed in the vector LE implementation.
There was already logic to distinguish between unary and "normal"
vmrg* vector shuffles, so this patch extends that logic to use a third
option: "swapped" vmrg* vector shuffles that are used for little
endian in place of the "normal" ones.
I've updated the vec-shuffle-le.ll test to check for the expected
register ordering on the generated instructions.
This bug was discovered when testing the LE and ELFv2 patches for
safety if they were backported to 3.4. A different vectorization
decision was made in 3.4 than on mainline trunk, and that exposed the
problem. I've verified this fix takes care of that issue.
llvm-svn: 213915
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 456f978..d596bda 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -926,31 +926,51 @@
/// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
/// a VMRGL* instruction with the specified unit size (1,2 or 4 bytes).
+/// The ShuffleKind distinguishes between big-endian merges with two
+/// different inputs (0), either-endian merges with two identical inputs (1),
+/// and little-endian merges with two different inputs (2). For the latter,
+/// the input operands are swapped (see PPCInstrAltivec.td).
bool PPC::isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
- bool isUnary, SelectionDAG &DAG) {
+ unsigned ShuffleKind, SelectionDAG &DAG) {
if (DAG.getTarget().getDataLayout()->isLittleEndian()) {
- if (!isUnary)
+ if (ShuffleKind == 1) // unary
+ return isVMerge(N, UnitSize, 0, 0);
+ else if (ShuffleKind == 2) // swapped
return isVMerge(N, UnitSize, 0, 16);
- return isVMerge(N, UnitSize, 0, 0);
+ else
+ return false;
} else {
- if (!isUnary)
+ if (ShuffleKind == 1) // unary
+ return isVMerge(N, UnitSize, 8, 8);
+ else if (ShuffleKind == 0) // normal
return isVMerge(N, UnitSize, 8, 24);
- return isVMerge(N, UnitSize, 8, 8);
+ else
+ return false;
}
}
/// isVMRGHShuffleMask - Return true if this is a shuffle mask suitable for
/// a VMRGH* instruction with the specified unit size (1,2 or 4 bytes).
+/// The ShuffleKind distinguishes between big-endian merges with two
+/// different inputs (0), either-endian merges with two identical inputs (1),
+/// and little-endian merges with two different inputs (2). For the latter,
+/// the input operands are swapped (see PPCInstrAltivec.td).
bool PPC::isVMRGHShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
- bool isUnary, SelectionDAG &DAG) {
+ unsigned ShuffleKind, SelectionDAG &DAG) {
if (DAG.getTarget().getDataLayout()->isLittleEndian()) {
- if (!isUnary)
+ if (ShuffleKind == 1) // unary
+ return isVMerge(N, UnitSize, 8, 8);
+ else if (ShuffleKind == 2) // swapped
return isVMerge(N, UnitSize, 8, 24);
- return isVMerge(N, UnitSize, 8, 8);
+ else
+ return false;
} else {
- if (!isUnary)
+ if (ShuffleKind == 1) // unary
+ return isVMerge(N, UnitSize, 0, 0);
+ else if (ShuffleKind == 0) // normal
return isVMerge(N, UnitSize, 0, 16);
- return isVMerge(N, UnitSize, 0, 0);
+ else
+ return false;
}
}
@@ -6021,12 +6041,12 @@
PPC::isVPKUWUMShuffleMask(SVOp, true, DAG) ||
PPC::isVPKUHUMShuffleMask(SVOp, true, DAG) ||
PPC::isVSLDOIShuffleMask(SVOp, true, DAG) != -1 ||
- PPC::isVMRGLShuffleMask(SVOp, 1, true, DAG) ||
- PPC::isVMRGLShuffleMask(SVOp, 2, true, DAG) ||
- PPC::isVMRGLShuffleMask(SVOp, 4, true, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 1, true, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 2, true, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 4, true, DAG)) {
+ PPC::isVMRGLShuffleMask(SVOp, 1, 1, DAG) ||
+ PPC::isVMRGLShuffleMask(SVOp, 2, 1, DAG) ||
+ PPC::isVMRGLShuffleMask(SVOp, 4, 1, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 1, 1, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 2, 1, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 4, 1, DAG)) {
return Op;
}
}
@@ -6034,15 +6054,16 @@
// Altivec has a variety of "shuffle immediates" that take two vector inputs
// and produce a fixed permutation. If any of these match, do not lower to
// VPERM.
+ unsigned int ShuffleKind = isLittleEndian ? 2 : 0;
if (PPC::isVPKUWUMShuffleMask(SVOp, false, DAG) ||
PPC::isVPKUHUMShuffleMask(SVOp, false, DAG) ||
PPC::isVSLDOIShuffleMask(SVOp, false, DAG) != -1 ||
- PPC::isVMRGLShuffleMask(SVOp, 1, false, DAG) ||
- PPC::isVMRGLShuffleMask(SVOp, 2, false, DAG) ||
- PPC::isVMRGLShuffleMask(SVOp, 4, false, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 1, false, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 2, false, DAG) ||
- PPC::isVMRGHShuffleMask(SVOp, 4, false, DAG))
+ PPC::isVMRGLShuffleMask(SVOp, 1, ShuffleKind, DAG) ||
+ PPC::isVMRGLShuffleMask(SVOp, 2, ShuffleKind, DAG) ||
+ PPC::isVMRGLShuffleMask(SVOp, 4, ShuffleKind, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 1, ShuffleKind, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 2, ShuffleKind, DAG) ||
+ PPC::isVMRGHShuffleMask(SVOp, 4, ShuffleKind, DAG))
return Op;
// Check to see if this is a shuffle of 4-byte values. If so, we can use our
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index ae8c300..2ac82bd 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -308,12 +308,12 @@
/// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
/// a VRGL* instruction with the specified unit size (1,2 or 4 bytes).
bool isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
- bool isUnary, SelectionDAG &DAG);
+ unsigned ShuffleKind, SelectionDAG &DAG);
/// isVMRGHShuffleMask - Return true if this is a shuffle mask suitable for
/// a VRGH* instruction with the specified unit size (1,2 or 4 bytes).
bool isVMRGHShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
- bool isUnary, SelectionDAG &DAG);
+ unsigned ShuffleKind, SelectionDAG &DAG);
/// isVSLDOIShuffleMask - If this is a vsldoi shuffle mask, return the shift
/// amount, otherwise return -1.
diff --git a/llvm/lib/Target/PowerPC/PPCInstrAltivec.td b/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
index dce46d8..0924cd8 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrAltivec.td
@@ -44,65 +44,81 @@
def vmrglb_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 1, false,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 0, *CurDAG);
}]>;
def vmrglh_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 2, false,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 0, *CurDAG);
}]>;
def vmrglw_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 4, false,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 0, *CurDAG);
}]>;
def vmrghb_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 1, false,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 0, *CurDAG);
}]>;
def vmrghh_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 2, false,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 0, *CurDAG);
}]>;
def vmrghw_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 4, false,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 0, *CurDAG);
}]>;
def vmrglb_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 1, true,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 1, *CurDAG);
}]>;
def vmrglh_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle node:$lhs, node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 2, true,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 1, *CurDAG);
}]>;
def vmrglw_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle node:$lhs, node:$rhs), [{
- return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 4, true,
- *CurDAG);
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 1, *CurDAG);
}]>;
def vmrghb_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle node:$lhs, node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 1, true,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 1, *CurDAG);
}]>;
def vmrghh_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle node:$lhs, node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 2, true,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 1, *CurDAG);
}]>;
def vmrghw_unary_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
(vector_shuffle node:$lhs, node:$rhs), [{
- return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 4, true,
- *CurDAG);
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 1, *CurDAG);
+}]>;
+
+
+// These fragments are provided for little-endian, where the inputs must be
+// swapped for correct semantics.
+def vmrglb_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle (v16i8 node:$lhs), node:$rhs), [{
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 2, *CurDAG);
+}]>;
+def vmrglh_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle node:$lhs, node:$rhs), [{
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 2, *CurDAG);
+}]>;
+def vmrglw_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle node:$lhs, node:$rhs), [{
+ return PPC::isVMRGLShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 2, *CurDAG);
+}]>;
+def vmrghb_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle node:$lhs, node:$rhs), [{
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 1, 2, *CurDAG);
+}]>;
+def vmrghh_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle node:$lhs, node:$rhs), [{
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 2, 2, *CurDAG);
+}]>;
+def vmrghw_swapped_shuffle : PatFrag<(ops node:$lhs, node:$rhs),
+ (vector_shuffle node:$lhs, node:$rhs), [{
+ return PPC::isVMRGHShuffleMask(cast<ShuffleVectorSDNode>(N), 4, 2, *CurDAG);
}]>;
@@ -803,6 +819,22 @@
def:Pat<(vmrghw_unary_shuffle v16i8:$vA, undef),
(VMRGHW $vA, $vA)>;
+// Match vmrg*(y,x), i.e., swapped operands. These fragments
+// are matched for little-endian, where the inputs must be
+// swapped for correct semantics.
+def:Pat<(vmrglb_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGLB $vB, $vA)>;
+def:Pat<(vmrglh_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGLH $vB, $vA)>;
+def:Pat<(vmrglw_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGLW $vB, $vA)>;
+def:Pat<(vmrghb_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGHB $vB, $vA)>;
+def:Pat<(vmrghh_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGHH $vB, $vA)>;
+def:Pat<(vmrghw_swapped_shuffle v16i8:$vA, v16i8:$vB),
+ (VMRGHW $vB, $vA)>;
+
// Logical Operations
def : Pat<(vnot_ppc v4i32:$vA), (VNOR $vA, $vA)>;