Fix PPC unaligned 64-bit loads and stores
PPC64 supports unaligned loads and stores of 64-bit values, but
in order to use the r+i forms, the offset must be a multiple of 4.
Unfortunately, this cannot always be determined by examining the
immediate itself because it might be available only via a TOC entry.
In order to get around this issue, we additionally predicate the
selection of the r+i form on the alignment of the load or store
(forcing it to be at least 4 in order to select the r+i form).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177338 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index 460e943..3f181aa 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -278,6 +278,38 @@
return N->getZExtValue() == (uint64_t)(int)N->getZExtValue();
}], HI16>;
+// Some r+i load/store instructions (such as LD, STD, LDU, etc.) that require
+// restricted memrix (offset/4) constants are alignment sensitive. If these
+// offsets are hidden behind TOC entries than the values of the lower-order
+// bits cannot be checked directly. As a result, we need to also incorporate
+// an alignment check into the relevant patterns.
+
+def aligned4load : PatFrag<(ops node:$ptr), (load node:$ptr), [{
+ return cast<LoadSDNode>(N)->getAlignment() >= 4;
+}]>;
+def aligned4store : PatFrag<(ops node:$val, node:$ptr),
+ (store node:$val, node:$ptr), [{
+ return cast<StoreSDNode>(N)->getAlignment() >= 4;
+}]>;
+def aligned4sextloadi32 : PatFrag<(ops node:$ptr), (sextloadi32 node:$ptr), [{
+ return cast<LoadSDNode>(N)->getAlignment() >= 4;
+}]>;
+def aligned4pre_store : PatFrag<
+ (ops node:$val, node:$base, node:$offset),
+ (pre_store node:$val, node:$base, node:$offset), [{
+ return cast<StoreSDNode>(N)->getAlignment() >= 4;
+}]>;
+
+def unaligned4load : PatFrag<(ops node:$ptr), (load node:$ptr), [{
+ return cast<LoadSDNode>(N)->getAlignment() < 4;
+}]>;
+def unaligned4store : PatFrag<(ops node:$val, node:$ptr),
+ (store node:$val, node:$ptr), [{
+ return cast<StoreSDNode>(N)->getAlignment() < 4;
+}]>;
+def unaligned4sextloadi32 : PatFrag<(ops node:$ptr), (sextloadi32 node:$ptr), [{
+ return cast<LoadSDNode>(N)->getAlignment() < 4;
+}]>;
//===----------------------------------------------------------------------===//
// PowerPC Flag Definitions.