diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -901,6 +901,7 @@
Value *LibCallSimplifier::optimizeMemChr(CallInst *CI, IRBuilder<> &B) {
Value *SrcStr = CI->getArgOperand(0);
+ Value *Char = CI->getArgOperand(1);
Value *Size = CI->getArgOperand(2);
annotateNonNullAndDereferenceable(CI, 0, Size, DL);
ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
@@ -923,7 +924,9 @@
// scan the string, as reading past the end of it is undefined and we can just
// return null if we don't find the char.
Str = Str.substr(0, LenC->getZExtValue());
-
+ bool OptForSize = CI->getFunction()->hasOptSize() ||
+ llvm::shouldOptimizeForSize(CI->getParent(), PSI, BFI,
+ PGSOQueryType::IRPass);
// If the char is variable but the input str and length are not we can turn
// this memchr call into a simple bit field test. Of course this only works
// when the return value is only checked against null.
@@ -934,18 +937,33 @@
// memchr("\r\n", C, 2) != nullptr -> (1 << C & ((1 << '\r') | (1 << '\n')))
// != 0
// after bounds check.
- if (!CharC && !Str.empty() && isOnlyUsedInZeroEqualityComparison(CI)) {
+ if (!OptForSize && !CharC && !Str.empty() &&
+ isOnlyUsedInZeroEqualityComparison(CI)) {
unsigned char Max =
*std::max_element(reinterpret_cast<const unsigned char *>(Str.begin()),
reinterpret_cast<const unsigned char *>(Str.end()));
// Make sure the bit field we're about to create fits in a register on the
// target.
- // FIXME: On a 64 bit architecture this prevents us from using the
- // interesting range of alpha ascii chars. We could do better by emitting
- // two bitfields or shifting the range by 64 if no lower chars are used.
- if (!DL.fitsInLegalInteger(Max + 1))
- return nullptr;
+ if (!DL.fitsInLegalInteger(Max + 1)) {
+ // Build chain of OR comparisons
+ // memchr("abcd", C, 4) != nullptr -> (C == 'a' | C == 'b' | C == 'c' |
+ // C == 'd') != 0
+ SmallVector<Value *, 2> CharCompares;
+ for (char C : Str)
+ CharCompares.push_back(
+ B.CreateICmpEQ(Char, ConstantInt::get(Char->getType(), C)));
+
+ Value *OrChain = CharCompares[0];
+ for (size_t i = 1; i < CharCompares.size(); i++)
+ OrChain = B.CreateOr(OrChain, CharCompares[i]);
+
+ return B.CreateIntToPtr(OrChain, CI->getType());
+
+ // FIXME: On a 64 bit architecture this prevents us from using the
+ // interesting range of alpha ascii chars. We could do better by emitting
+ // two bitfields or shifting the range by 64 if no lower chars are used.
+ }
// For the bit field use a power-of-2 type with at least 8 bits to avoid
// creating unnecessary illegal types.
diff --git a/llvm/test/Transforms/InstCombine/memchr-2.ll b/llvm/test/Transforms/InstCombine/memchr-2.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/memchr-2.ll
@@ -0,0 +1,102 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+@.str = private unnamed_addr constant [27 x i8] c"abcdefghijklmnopqrstuvwxyz\00", align 1
+@.str.1 = private unnamed_addr constant [2 x i8] c"\0D\0A", align 1
+
+declare i8* @strchr(i8*, i32)
+declare i8* @memchr(i8*, i32, i64)
+
+define zeroext i1 @memchr_n_equals_len(i32 %c) {
+; CHECK-LABEL: @memchr_n_equals_len(
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 [[C:%.*]], 0
+; CHECK-NEXT: [[TMP2:%.*]] = add i32 [[C]], -97
+; CHECK-NEXT: [[TMP3:%.*]] = icmp ult i32 [[TMP2]], 26
+; CHECK-NEXT: [[TMP4:%.*]] = or i1 [[TMP3]], [[TMP1]]
+; CHECK-NEXT: ret i1 [[TMP4]]
+;
+ %call = tail call i8* @strchr(i8* nonnull dereferenceable(27) getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 %c)
+ %cmp = icmp ne i8* %call, null
+ ret i1 %cmp
+}
+
+define zeroext i1 @memchr_n_equals_len2(i32 %c) {
+; CHECK-LABEL: @memchr_n_equals_len2(
+; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i32 [[C:%.*]], 13
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[C]], 10
+; CHECK-NEXT: [[TMP3:%.*]] = and i1 [[TMP1]], [[TMP2]]
+; CHECK-NEXT: ret i1 [[TMP3]]
+;
+ %call = tail call i8* @memchr(i8* nonnull dereferenceable(3) getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0), i32 %c, i64 2)
+ %cmp = icmp eq i8* %call, null
+ ret i1 %cmp
+}
+
+define zeroext i1 @memchr_n_less_than_len(i32 %c) {
+; CHECK-LABEL: @memchr_n_less_than_len(
+; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[C:%.*]], -97
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 15
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %call = tail call i8* @memchr(i8* getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 %c, i64 15)
+ %cmp = icmp ne i8* %call, null
+ ret i1 %cmp
+}
+
+
+define zeroext i1 @memchr_n_more_than_len(i32 %c) {
+; CHECK-LABEL: @memchr_n_more_than_len(
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 [[C:%.*]], 0
+; CHECK-NEXT: [[TMP2:%.*]] = add i32 [[C]], -97
+; CHECK-NEXT: [[TMP3:%.*]] = icmp ult i32 [[TMP2]], 26
+; CHECK-NEXT: [[TMP4:%.*]] = or i1 [[TMP3]], [[TMP1]]
+; CHECK-NEXT: ret i1 [[TMP4]]
+;
+ %call = tail call i8* @memchr(i8* getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 %c, i64 30)
+ %cmp = icmp ne i8* %call, null
+ ret i1 %cmp
+}
+
+; Negative test - no comparison with zero
+
+define i8* @memchr_no_zero_cmp(i32 %c) {
+; CHECK-LABEL: @memchr_no_zero_cmp(
+; CHECK-NEXT: [[MEMCHR:%.*]] = call i8* @memchr(i8* nonnull dereferenceable(27) getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 [[C:%.*]], i64 27)
+; CHECK-NEXT: ret i8* [[MEMCHR]]
+;
+ %call = tail call i8* @strchr(i8* nonnull dereferenceable(27) getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 %c)
+ ret i8* %call
+}
+
+define i8* @memchr_no_zero_cmp2(i32 %c) {
+; CHECK-LABEL: @memchr_no_zero_cmp2(
+; CHECK-NEXT: [[MEMCHR:%.*]] = call i8* @memchr(i8* nonnull dereferenceable(3) getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0), i32 [[C:%.*]], i64 3)
+; CHECK-NEXT: ret i8* [[MEMCHR]]
+;
+ %call = tail call i8* @strchr(i8* nonnull dereferenceable(3) getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0), i32 %c)
+ ret i8* %call
+}
+
+; Negative test - opt for size
+
+define zeroext i1 @memchr_n_equals_len_minsize(i32 %c) minsize {
+; CHECK-LABEL: @memchr_n_equals_len_minsize(
+; CHECK-NEXT: [[MEMCHR:%.*]] = call i8* @memchr(i8* nonnull dereferenceable(27) getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 [[C:%.*]], i64 27)
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8* [[MEMCHR]], null
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %call = tail call i8* @strchr(i8* nonnull dereferenceable(27) getelementptr inbounds ([27 x i8], [27 x i8]* @.str, i64 0, i64 0), i32 %c)
+ %cmp = icmp ne i8* %call, null
+ ret i1 %cmp
+}
+
+define zeroext i1 @memchr_n_equals_len2_minsize(i32 %c) minsize {
+; CHECK-LABEL: @memchr_n_equals_len2_minsize(
+; CHECK-NEXT: [[CALL:%.*]] = tail call i8* @memchr(i8* nonnull dereferenceable(3) getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0), i32 [[C:%.*]], i64 2)
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8* [[CALL]], null
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %call = tail call i8* @memchr(i8* nonnull dereferenceable(3) getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0), i32 %c, i64 2)
+ %cmp = icmp eq i8* %call, null
+ ret i1 %cmp
+}