From 0f8df9a9ceab274a94c794ac82733c79d0f13597 Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Sun, 4 Jan 2009 20:27:34 +0000 Subject: Run a post-pass that marks known function declarations by name. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61632 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SimplifyLibCalls.cpp | 443 +++++++++++++++++++++ .../SimplifyLibCalls/2009-01-04-Annotate.ll | 12 + 2 files changed, 455 insertions(+) create mode 100644 test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 8723208405..829d1344b1 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/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(); } @@ -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(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 2); + } else if (NameLen == 7 && !strcmp(NameStr, "strxfrm")) { + if (FTy->getNumParams() != 3 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0)) || + !isa(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(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(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } else if (NameLen == 6 && !strcmp(NameStr, "sscanf")) { + if (FTy->getNumParams() < 2 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 2); + } + break; + case 'r': + if (NameLen == 7 && !strcmp(NameStr, "realloc")) { + if (FTy->getNumParams() != 1 || + !isa(FTy->getParamType(0)) || + !isa(FTy->getReturnType())) + continue; + setDoesNotThrow(F); + setDoesNotAlias(F, 0); + setDoesNotCapture(F, 1); + } else if (NameLen == 4 && !strcmp(NameStr, "read")) { + if (FTy->getNumParams() != 3 || + !isa(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } else if (NameLen == 6 && !strcmp(NameStr, "rename")) { + if (FTy->getNumParams() != 2 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 2); + } + break; + case 'b': + if (NameLen == 5 && !strcmp(NameStr, "bcopy")) { + if (FTy->getNumParams() != 3 || + !isa(FTy->getParamType(0)) || + !isa(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + setDoesNotCapture(F, 2); + } else if (NameLen == 4 && !strcmp(NameStr, "bcmp")) { + if (FTy->getNumParams() != 3 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } + break; + case 'c': + if (NameLen == 6 && !strcmp(NameStr, "calloc")) { + if (FTy->getNumParams() != 2 || + !isa(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(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setOnlyReadsMemory(F); + setDoesNotCapture(F, 1); + } else if (NameLen == 6 && !strcmp(NameStr, "access")) { + if (FTy->getNumParams() != 2 || + !isa(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(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(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 2); + } else if (NameLen == 5 && !strcmp(NameStr, "fgets")) { + if (FTy->getNumParams() != 3 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0)) || + !isa(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + setDoesNotCapture(F, 2); + } else if (NameLen == 6 && !strcmp(NameStr, "fscanf")) { + if (FTy->getNumParams() < 2 || + !isa(FTy->getParamType(0)) || + !isa(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } else if (NameLen == 6 && !strcmp(NameStr, "getenv")) { + if (!FTy->getNumParams() != 1 || + !isa(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 2); + } else if (NameLen == 6 && !strcmp(NameStr, "unlink")) { + if (!FTy->getNumParams() != 1 || + !isa(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } + break; + case 'p': + if (NameLen == 4 && !strcmp(NameStr, "putc")) { + if (!FTy->getNumParams() != 2 || + !isa(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(FTy->getParamType(0))) + continue; + setDoesNotThrow(F); + setDoesNotCapture(F, 1); + } + break; + case 'v': + if (NameLen == 6 && !strcmp(NameStr, "vscanf")) { + if (!FTy->getNumParams() != 2 || + !isa(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(FTy->getParamType(1)) || + !isa(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(FTy->getParamType(1))) + continue; + setDoesNotThrow(F); + setDoesNotAlias(F, 0); + } + break; + case 't': + if (NameLen == 7 && !strcmp(NameStr, "tmpfile")) { + if (!isa(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/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll b/test/Transforms/SimplifyLibCalls/2009-01-04-Annotate.ll new file mode 100644 index 0000000000..ac2c89dd7f --- /dev/null +++ b/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(...) -- cgit v1.2.3-18-g5258