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-rw-r--r--llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp443
-rw-r--r--llvm/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll12
2 files changed, 455 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 87232084051..829d1344b11 100644
--- a/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -34,6 +34,7 @@
using namespace llvm;
STATISTIC(NumSimplified, "Number of library calls simplified");
+STATISTIC(NumAnnotated, "Number of attributes added to library functions");
//===----------------------------------------------------------------------===//
// Optimizer Base Class
@@ -1288,6 +1289,8 @@ namespace {
// Formatting and IO Optimizations
SPrintFOpt SPrintF; PrintFOpt PrintF;
FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
+
+ bool Modified; // This is only used by doFinalization.
public:
static char ID; // Pass identification
SimplifyLibCalls() : FunctionPass(&ID) {}
@@ -1295,6 +1298,13 @@ namespace {
void InitOptimizations();
bool runOnFunction(Function &F);
+ void setDoesNotAccessMemory(Function &F);
+ void setOnlyReadsMemory(Function &F);
+ void setDoesNotThrow(Function &F);
+ void setDoesNotCapture(Function &F, unsigned n);
+ void setDoesNotAlias(Function &F, unsigned n);
+ bool doFinalization(Module &M);
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<TargetData>();
}
@@ -1440,6 +1450,439 @@ bool SimplifyLibCalls::runOnFunction(Function &F) {
return Changed;
}
+// Utility methods for doFinalization.
+
+void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
+ if (!F.doesNotAccessMemory()) {
+ F.setDoesNotAccessMemory();
+ ++NumAnnotated;
+ Modified = true;
+ }
+}
+void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
+ if (!F.onlyReadsMemory()) {
+ F.setOnlyReadsMemory();
+ ++NumAnnotated;
+ Modified = true;
+ }
+}
+void SimplifyLibCalls::setDoesNotThrow(Function &F) {
+ if (!F.doesNotThrow()) {
+ F.setDoesNotThrow();
+ ++NumAnnotated;
+ Modified = true;
+ }
+}
+void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
+ if (!F.doesNotCapture(n)) {
+ F.setDoesNotCapture(n);
+ ++NumAnnotated;
+ Modified = true;
+ }
+}
+void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
+ if (!F.doesNotAlias(n)) {
+ F.setDoesNotAlias(n);
+ ++NumAnnotated;
+ Modified = true;
+ }
+}
+
+/// doFinalization - Add attributes to well-known functions.
+///
+bool SimplifyLibCalls::doFinalization(Module &M) {
+ Modified = false;
+ for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
+ Function &F = *I;
+ if (!F.isDeclaration())
+ continue;
+
+ unsigned NameLen = F.getNameLen();
+ if (!NameLen)
+ continue;
+
+ const FunctionType *FTy = F.getFunctionType();
+
+ const char *NameStr = F.getNameStart();
+ switch (NameStr[0]) {
+ case 's':
+ if (NameLen == 6 && !strcmp(NameStr, "strlen")) {
+ if (FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "strcpy")) ||
+ (NameLen == 6 && !strcmp(NameStr, "stpcpy")) ||
+ (NameLen == 6 && !strcmp(NameStr, "strcat")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strncat")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strncpy"))) {
+ if (FTy->getNumParams() < 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 7 && !strcmp(NameStr, "strxfrm")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "strcmp")) ||
+ (NameLen == 6 && !strcmp(NameStr, "strspn")) ||
+ (NameLen == 6 && !strcmp(NameStr, "strtol")) ||
+ (NameLen == 6 && !strcmp(NameStr, "strtod")) ||
+ (NameLen == 6 && !strcmp(NameStr, "strtof")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strtoul")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strtoll")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strtold")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strncmp")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strcspn")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strcoll")) ||
+ (NameLen == 8 && !strcmp(NameStr, "strtoull")) ||
+ (NameLen == 10 && !strcmp(NameStr, "strcasecmp")) ||
+ (NameLen == 11 && !strcmp(NameStr, "strncasecmp"))) {
+ if (FTy->getNumParams() < 2 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "strstr")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strpbrk"))) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "strtok")) ||
+ (NameLen == 7 && !strcmp(NameStr, "strtok_r"))) {
+ if (FTy->getNumParams() < 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 5 && !strcmp(NameStr, "scanf")) ||
+ (NameLen == 6 && !strcmp(NameStr, "setbuf")) ||
+ (NameLen == 7 && !strcmp(NameStr, "setvbuf"))) {
+ if (FTy->getNumParams() < 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if (NameLen == 6 && !strcmp(NameStr, "sscanf")) {
+ if (FTy->getNumParams() < 2 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'm':
+ if (NameLen == 6 && !strcmp(NameStr, "memcmp")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "memchr")) ||
+ (NameLen == 7 && !strcmp(NameStr, "memrchr"))) {
+ if (FTy->getNumParams() != 3)
+ continue;
+ setOnlyReadsMemory(F);
+ setDoesNotThrow(F);
+ } else if ((NameLen == 6 && !strcmp(NameStr, "memcpy")) ||
+ (NameLen == 7 && !strcmp(NameStr, "memccpy")) ||
+ (NameLen == 7 && !strcmp(NameStr, "memmove"))) {
+ if (FTy->getNumParams() < 3 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'r':
+ if (NameLen == 7 && !strcmp(NameStr, "realloc")) {
+ if (FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getReturnType()))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ setDoesNotCapture(F, 1);
+ } else if (NameLen == 4 && !strcmp(NameStr, "read")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 5 && !strcmp(NameStr, "rmdir")) ||
+ (NameLen == 6 && !strcmp(NameStr, "rewind")) ||
+ (NameLen == 6 && !strcmp(NameStr, "remove"))) {
+ if (FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if (NameLen == 6 && !strcmp(NameStr, "rename")) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'w':
+ if (NameLen == 5 && !strcmp(NameStr, "write")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'b':
+ if (NameLen == 5 && !strcmp(NameStr, "bcopy")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 4 && !strcmp(NameStr, "bcmp")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 5 && !strcmp(NameStr, "bzero")) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ }
+ break;
+ case 'c':
+ if (NameLen == 6 && !strcmp(NameStr, "calloc")) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getReturnType()))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ } else if ((NameLen == 5 && !strcmp(NameStr, "chown")) ||
+ (NameLen == 8 && !strcmp(NameStr, "clearerr")) ||
+ (NameLen == 8 && !strcmp(NameStr, "closedir"))) {
+ if (FTy->getNumParams() == 0 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ }
+ break;
+ case 'a':
+ if ((NameLen == 4 && !strcmp(NameStr, "atoi")) ||
+ (NameLen == 4 && !strcmp(NameStr, "atol")) ||
+ (NameLen == 4 && !strcmp(NameStr, "atof")) ||
+ (NameLen == 5 && !strcmp(NameStr, "atoll"))) {
+ if (FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 1);
+ } else if (NameLen == 6 && !strcmp(NameStr, "access")) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ }
+ break;
+ case 'f':
+ if ((NameLen == 5 && !strcmp(NameStr, "fopen")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fdopen"))) {
+ if (!isa<PointerType>(FTy->getReturnType()))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ } else if ((NameLen == 4 && !strcmp(NameStr, "feof")) ||
+ (NameLen == 4 && !strcmp(NameStr, "free")) ||
+ (NameLen == 5 && !strcmp(NameStr, "fseek")) ||
+ (NameLen == 5 && !strcmp(NameStr, "ftell")) ||
+ (NameLen == 5 && !strcmp(NameStr, "fgetc")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fseeko")) ||
+ (NameLen == 6 && !strcmp(NameStr, "ftello")) ||
+ (NameLen == 6 && !strcmp(NameStr, "ferror")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fileno")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fflush")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fclose"))) {
+ if (FTy->getNumParams() == 0 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if ((NameLen == 5 && !strcmp(NameStr, "fputc")) ||
+ (NameLen == 5 && !strcmp(NameStr, "fputs"))) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 5 && !strcmp(NameStr, "fgets")) {
+ if (FTy->getNumParams() != 3 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(2)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 3);
+ } else if ((NameLen == 5 && !strcmp(NameStr, "fread")) ||
+ (NameLen == 6 && !strcmp(NameStr, "fwrite"))) {
+ if (FTy->getNumParams() != 4 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(3)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 4);
+ } else if ((NameLen == 7 && !strcmp(NameStr, "fgetpos")) ||
+ (NameLen == 7 && !strcmp(NameStr, "fsetpos"))) {
+ if (FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 6 && !strcmp(NameStr, "fscanf")) {
+ if (FTy->getNumParams() < 2 ||
+ !isa<PointerType>(FTy->getParamType(0)) ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'g':
+ if ((NameLen == 4 && !strcmp(NameStr, "getc")) ||
+ (NameLen == 10 && !strcmp(NameStr, "getlogin_r"))) {
+ if (FTy->getNumParams() == 0 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if (NameLen == 6 && !strcmp(NameStr, "getenv")) {
+ if (!FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setOnlyReadsMemory(F);
+ setDoesNotCapture(F, 0);
+ }
+ break;
+ case 'u':
+ if (NameLen == 4 && !strcmp(NameStr, "ungetc")) {
+ if (!FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if (NameLen == 6 && !strcmp(NameStr, "unlink")) {
+ if (!FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ }
+ break;
+ case 'p':
+ if (NameLen == 4 && !strcmp(NameStr, "putc")) {
+ if (!FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 2);
+ } else if ((NameLen == 4 && !strcmp(NameStr, "puts")) ||
+ (NameLen == 6 && !strcmp(NameStr, "perror"))) {
+ if (!FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(0)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ }
+ break;
+ case 'v':
+ if (NameLen == 6 && !strcmp(NameStr, "vscanf")) {
+ if (!FTy->getNumParams() != 2 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ } else if ((NameLen == 7 && !strcmp(NameStr, "vsscanf")) ||
+ (NameLen == 7 && !strcmp(NameStr, "vfscanf"))) {
+ if (!FTy->getNumParams() != 4 ||
+ !isa<PointerType>(FTy->getParamType(1)) ||
+ !isa<PointerType>(FTy->getParamType(2)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotCapture(F, 1);
+ setDoesNotCapture(F, 2);
+ }
+ break;
+ case 'o':
+ if (NameLen == 7 && !strcmp(NameStr, "opendir")) {
+ // The description of fdopendir sounds like opening the same fd
+ // twice might result in the same DIR* !
+ if (FTy->getNumParams() != 1 ||
+ !isa<PointerType>(FTy->getParamType(1)))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ }
+ break;
+ case 't':
+ if (NameLen == 7 && !strcmp(NameStr, "tmpfile")) {
+ if (!isa<PointerType>(FTy->getReturnType()))
+ continue;
+ setDoesNotThrow(F);
+ setDoesNotAlias(F, 0);
+ }
+ case 'h':
+ if ((NameLen == 5 && !strcmp(NameStr, "htonl")) ||
+ (NameLen == 5 && !strcmp(NameStr, "htons"))) {
+ setDoesNotThrow(F);
+ setDoesNotAccessMemory(F);
+ }
+ break;
+ case 'n':
+ if ((NameLen == 5 && !strcmp(NameStr, "ntohl")) ||
+ (NameLen == 5 && !strcmp(NameStr, "ntohs"))) {
+ setDoesNotThrow(F);
+ setDoesNotAccessMemory(F);
+ }
+ break;
+ }
+ }
+ return Modified;
+}
// TODO:
// Additional cases that we need to add to this file:
diff --git a/llvm/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll b/llvm/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll
new file mode 100644
index 00000000000..ac2c89dd7f7
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | opt -simplify-libcalls | llvm-dis > %t
+; RUN: grep noalias %t | count 2
+; RUN: grep nocapture %t | count 2
+; RUN: grep nounwind %t | count 3
+; RUN: grep readonly %t | count 1
+
+declare i8* @fopen(i8*, i8*)
+declare i8 @strlen(i8*)
+declare i32* @realloc(i32*)
+
+; Test deliberately wrong declaration
+declare i32 @strcpy(...)
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