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[LoopIdiom] Fix a DL-related crash in optimizeCRCLoop
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3 files changed

+70
-24
lines changed

3 files changed

+70
-24
lines changed

‎llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp‎

Lines changed: 9 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -1545,6 +1545,12 @@ bool LoopIdiomRecognize::optimizeCRCLoop(const PolynomialInfo &Info) {
15451545
if (TT.getArch() == Triple::hexagon)
15461546
return false;
15471547

1548+
// Check that the DataLayout allows us to index into the new 256-entry CRC
1549+
// table.
1550+
Type *IdxTy = SE->getDataLayout().getIndexType(M.getContext(), 0);
1551+
if (IdxTy->getIntegerBitWidth() < 8)
1552+
return false;
1553+
15481554
// First, create a new GlobalVariable corresponding to the
15491555
// Sarwate-lookup-table.
15501556
Type *CRCTy = Info.LHS->getType();
@@ -1598,11 +1604,8 @@ bool LoopIdiomRecognize::optimizeCRCLoop(const PolynomialInfo &Info) {
15981604
// crc = (crc << 8) ^ tbl[(iv'th byte of data) ^ (top byte of crc)]
15991605
{
16001606
auto LoByte = [](IRBuilderBase &Builder, Value *Op, const Twine &Name) {
1601-
Type *OpTy = Op->getType();
1602-
unsigned OpBW = OpTy->getIntegerBitWidth();
1603-
return OpBW > 8
1604-
? Builder.CreateAnd(Op, ConstantInt::get(OpTy, 0XFF), Name)
1605-
: Op;
1607+
return Builder.CreateZExtOrTrunc(
1608+
Op, IntegerType::getInt8Ty(Op->getContext()));
16061609
};
16071610
auto HiIdx = [LoByte, CRCBW](IRBuilderBase &Builder, Value *Op,
16081611
const Twine &Name) {
@@ -1654,9 +1657,7 @@ bool LoopIdiomRecognize::optimizeCRCLoop(const PolynomialInfo &Info) {
16541657
: LoByte(Builder, Indexer, "indexer.lo");
16551658

16561659
// Always index into a GEP using the index type.
1657-
Indexer = Builder.CreateZExt(
1658-
Indexer, SE->getDataLayout().getIndexType(GV->getType()),
1659-
"indexer.ext");
1660+
Indexer = Builder.CreateZExt(Indexer, IdxTy, "indexer.ext");
16601661

16611662
// CRCTableLd = CRCTable[(iv'th byte of data) ^ (top|bottom) byte of CRC].
16621663
Value *CRCTableGEP =

‎llvm/test/Transforms/LoopIdiom/cyclic-redundancy-check-dl.ll‎

Lines changed: 49 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,9 +1,54 @@
1-
; REQUIRES: asserts
2-
; RUN: not --crash opt -passes=loop-idiom -S %s
3-
4-
target datalayout = "p:16:16"
1+
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 6
2+
; RUN: opt -passes=loop-idiom -data-layout="p:16:16" -S %s | FileCheck %s --check-prefix=CHECK-i16
3+
; RUN: opt -passes=loop-idiom -data-layout="p:1:8" -S %s | FileCheck %s --check-prefix=CHECK-i1
54

5+
;.
6+
; CHECK-i16: @.crctable = private constant [256 x i32] zeroinitializer
7+
;.
68
define void @test_with_dl() {
9+
; CHECK-i16-LABEL: define void @test_with_dl() {
10+
; CHECK-i16-NEXT: [[ENTRY:.*]]:
11+
; CHECK-i16-NEXT: br label %[[PH:.*]]
12+
; CHECK-i16: [[PH_LOOPEXIT:.*]]:
13+
; CHECK-i16-NEXT: [[CRC_NEXT_LCSSA:%.*]] = phi i32 [ [[CRC_NEXT3:%.*]], %[[LOOP:.*]] ]
14+
; CHECK-i16-NEXT: br label %[[PH]]
15+
; CHECK-i16: [[PH]]:
16+
; CHECK-i16-NEXT: [[CRC_USE:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[CRC_NEXT_LCSSA]], %[[PH_LOOPEXIT]] ]
17+
; CHECK-i16-NEXT: br label %[[LOOP]]
18+
; CHECK-i16: [[LOOP]]:
19+
; CHECK-i16-NEXT: [[IV:%.*]] = phi i16 [ 0, %[[PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
20+
; CHECK-i16-NEXT: [[CRC2:%.*]] = phi i32 [ 0, %[[PH]] ], [ [[CRC_NEXT3]], %[[LOOP]] ]
21+
; CHECK-i16-NEXT: [[TMP0:%.*]] = trunc i32 [[CRC2]] to i8
22+
; CHECK-i16-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i16
23+
; CHECK-i16-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i32, ptr @.crctable, i16 [[INDEXER_EXT]]
24+
; CHECK-i16-NEXT: [[TBL_LD:%.*]] = load i32, ptr [[TBL_PTRADD]], align 4
25+
; CHECK-i16-NEXT: [[CRC_LE_SHIFT:%.*]] = lshr i32 [[CRC2]], 8
26+
; CHECK-i16-NEXT: [[CRC_NEXT3]] = xor i32 [[CRC_LE_SHIFT]], [[TBL_LD]]
27+
; CHECK-i16-NEXT: [[IV_NEXT]] = add i16 [[IV]], 1
28+
; CHECK-i16-NEXT: [[EXIT_COND1:%.*]] = icmp ne i16 [[IV]], 0
29+
; CHECK-i16-NEXT: br i1 [[EXIT_COND1]], label %[[LOOP]], label %[[PH_LOOPEXIT]]
30+
;
31+
; CHECK-i1-LABEL: define void @test_with_dl() {
32+
; CHECK-i1-NEXT: [[ENTRY:.*]]:
33+
; CHECK-i1-NEXT: br label %[[PH:.*]]
34+
; CHECK-i1: [[PH_LOOPEXIT:.*]]:
35+
; CHECK-i1-NEXT: [[CRC_NEXT_LCSSA:%.*]] = phi i32 [ [[CRC_NEXT:%.*]], %[[LOOP:.*]] ]
36+
; CHECK-i1-NEXT: br label %[[PH]]
37+
; CHECK-i1: [[PH]]:
38+
; CHECK-i1-NEXT: [[CRC_USE:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[CRC_NEXT_LCSSA]], %[[PH_LOOPEXIT]] ]
39+
; CHECK-i1-NEXT: br label %[[LOOP]]
40+
; CHECK-i1: [[LOOP]]:
41+
; CHECK-i1-NEXT: [[IV:%.*]] = phi i16 [ 0, %[[PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
42+
; CHECK-i1-NEXT: [[CRC:%.*]] = phi i32 [ 0, %[[PH]] ], [ [[CRC_NEXT]], %[[LOOP]] ]
43+
; CHECK-i1-NEXT: [[LSHR_CRC_1:%.*]] = lshr i32 [[CRC]], 1
44+
; CHECK-i1-NEXT: [[CRC_AND_1:%.*]] = and i32 [[CRC]], 1
45+
; CHECK-i1-NEXT: [[SB_CHECK:%.*]] = icmp eq i32 [[CRC_AND_1]], 0
46+
; CHECK-i1-NEXT: [[XOR:%.*]] = xor i32 [[LSHR_CRC_1]], 0
47+
; CHECK-i1-NEXT: [[CRC_NEXT]] = select i1 [[SB_CHECK]], i32 [[LSHR_CRC_1]], i32 [[XOR]]
48+
; CHECK-i1-NEXT: [[IV_NEXT]] = add i16 [[IV]], 1
49+
; CHECK-i1-NEXT: [[EXIT_COND:%.*]] = icmp ult i16 [[IV]], 7
50+
; CHECK-i1-NEXT: br i1 [[EXIT_COND]], label %[[LOOP]], label %[[PH_LOOPEXIT]]
51+
;
752
entry:
853
br label %ph
954

‎llvm/test/Transforms/LoopIdiom/cyclic-redundancy-check.ll‎

Lines changed: 12 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -118,8 +118,8 @@ define i16 @crc16.le.tc16(i16 %msg, i16 %checksum) {
118118
; CHECK-NEXT: [[IV_INDEXER:%.*]] = zext i8 [[IV_BITS]] to i16
119119
; CHECK-NEXT: [[DATA_INDEXER:%.*]] = lshr i16 [[MSG]], [[IV_INDEXER]]
120120
; CHECK-NEXT: [[CRC_DATA_INDEXER:%.*]] = xor i16 [[DATA_INDEXER]], [[CRC2]]
121-
; CHECK-NEXT: [[INDEXER_LO:%.*]] = and i16 [[CRC_DATA_INDEXER]], 255
122-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i16 [[INDEXER_LO]] to i64
121+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i16 [[CRC_DATA_INDEXER]] to i8
122+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
123123
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i16, ptr @.crctable.2, i64 [[INDEXER_EXT]]
124124
; CHECK-NEXT: [[TBL_LD:%.*]] = load i16, ptr [[TBL_PTRADD]], align 2
125125
; CHECK-NEXT: [[CRC_LE_SHIFT:%.*]] = lshr i16 [[CRC2]], 8
@@ -166,8 +166,8 @@ define i8 @crc8.le.tc16(i16 %msg, i8 %checksum) {
166166
; CHECK-NEXT: [[DATA_INDEXER:%.*]] = lshr i16 [[MSG]], [[IV_INDEXER]]
167167
; CHECK-NEXT: [[CRC_INDEXER_CAST:%.*]] = zext i8 [[CRC2]] to i16
168168
; CHECK-NEXT: [[CRC_DATA_INDEXER:%.*]] = xor i16 [[DATA_INDEXER]], [[CRC_INDEXER_CAST]]
169-
; CHECK-NEXT: [[INDEXER_LO:%.*]] = and i16 [[CRC_DATA_INDEXER]], 255
170-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i16 [[INDEXER_LO]] to i64
169+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i16 [[CRC_DATA_INDEXER]] to i8
170+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
171171
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i8, ptr @.crctable.3, i64 [[INDEXER_EXT]]
172172
; CHECK-NEXT: [[TBL_LD]] = load i8, ptr [[TBL_PTRADD]], align 1
173173
; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i8 [[IV]], 1
@@ -212,8 +212,8 @@ define i16 @crc16.be.tc8.crc.init.li(i16 %checksum, i8 %msg) {
212212
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
213213
; CHECK-NEXT: [[CRC2:%.*]] = phi i16 [ [[CRC_INIT]], %[[ENTRY]] ], [ [[CRC_NEXT3:%.*]], %[[LOOP]] ]
214214
; CHECK-NEXT: [[INDEXER_HI:%.*]] = lshr i16 [[CRC2]], 8
215-
; CHECK-NEXT: [[INDEXER_HI_LO_BYTE:%.*]] = and i16 [[INDEXER_HI]], 255
216-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i16 [[INDEXER_HI_LO_BYTE]] to i64
215+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i16 [[INDEXER_HI]] to i8
216+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
217217
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i16, ptr @.crctable.4, i64 [[INDEXER_EXT]]
218218
; CHECK-NEXT: [[TBL_LD:%.*]] = load i16, ptr [[TBL_PTRADD]], align 2
219219
; CHECK-NEXT: [[CRC_BE_SHIFT:%.*]] = shl i16 [[CRC2]], 8
@@ -255,8 +255,8 @@ define i16 @crc16.be.tc8.crc.init.arg(i16 %crc.init) {
255255
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
256256
; CHECK-NEXT: [[CRC2:%.*]] = phi i16 [ [[CRC_INIT]], %[[ENTRY]] ], [ [[CRC_NEXT3:%.*]], %[[LOOP]] ]
257257
; CHECK-NEXT: [[INDEXER_HI:%.*]] = lshr i16 [[CRC2]], 8
258-
; CHECK-NEXT: [[INDEXER_HI_LO_BYTE:%.*]] = and i16 [[INDEXER_HI]], 255
259-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i16 [[INDEXER_HI_LO_BYTE]] to i64
258+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i16 [[INDEXER_HI]] to i8
259+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
260260
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i16, ptr @.crctable.5, i64 [[INDEXER_EXT]]
261261
; CHECK-NEXT: [[TBL_LD:%.*]] = load i16, ptr [[TBL_PTRADD]], align 2
262262
; CHECK-NEXT: [[CRC_BE_SHIFT:%.*]] = shl i16 [[CRC2]], 8
@@ -295,8 +295,8 @@ define i16 @crc16.be.tc8.crc.init.arg.flipped.sb.check(i16 %crc.init) {
295295
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
296296
; CHECK-NEXT: [[CRC2:%.*]] = phi i16 [ [[CRC_INIT]], %[[ENTRY]] ], [ [[CRC_NEXT3:%.*]], %[[LOOP]] ]
297297
; CHECK-NEXT: [[INDEXER_HI:%.*]] = lshr i16 [[CRC2]], 8
298-
; CHECK-NEXT: [[INDEXER_HI_LO_BYTE:%.*]] = and i16 [[INDEXER_HI]], 255
299-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i16 [[INDEXER_HI_LO_BYTE]] to i64
298+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i16 [[INDEXER_HI]] to i8
299+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
300300
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i16, ptr @.crctable.6, i64 [[INDEXER_EXT]]
301301
; CHECK-NEXT: [[TBL_LD:%.*]] = load i16, ptr [[TBL_PTRADD]], align 2
302302
; CHECK-NEXT: [[CRC_BE_SHIFT:%.*]] = shl i16 [[CRC2]], 8
@@ -406,8 +406,8 @@ define i32 @crc32.le.tc8.data32(i32 %checksum, i32 %msg) {
406406
; CHECK-NEXT: [[IV_INDEXER:%.*]] = zext i8 [[IV_BITS]] to i32
407407
; CHECK-NEXT: [[DATA_INDEXER:%.*]] = lshr i32 [[MSG]], [[IV_INDEXER]]
408408
; CHECK-NEXT: [[CRC_DATA_INDEXER:%.*]] = xor i32 [[DATA_INDEXER]], [[CRC2]]
409-
; CHECK-NEXT: [[INDEXER_LO:%.*]] = and i32 [[CRC_DATA_INDEXER]], 255
410-
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i32 [[INDEXER_LO]] to i64
409+
; CHECK-NEXT: [[TMP0:%.*]] = trunc i32 [[CRC_DATA_INDEXER]] to i8
410+
; CHECK-NEXT: [[INDEXER_EXT:%.*]] = zext i8 [[TMP0]] to i64
411411
; CHECK-NEXT: [[TBL_PTRADD:%.*]] = getelementptr inbounds i32, ptr @.crctable.8, i64 [[INDEXER_EXT]]
412412
; CHECK-NEXT: [[TBL_LD:%.*]] = load i32, ptr [[TBL_PTRADD]], align 4
413413
; CHECK-NEXT: [[CRC_LE_SHIFT:%.*]] = lshr i32 [[CRC2]], 8

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