[llvm-commits] [llvm] r50521 - /llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
Chris Lattner
sabre at nondot.org
Wed Apr 30 23:39:12 PDT 2008
Author: lattner
Date: Thu May 1 01:39:12 2008
New Revision: 50521
URL: http://llvm.org/viewvc/llvm-project?rev=50521&view=rev
Log:
1) add '-debug' output
2) Return NULL instead of false in several places for tidiness.
3) fix a bug optimizing sprintf(p, "%c", x)
Modified:
llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp?rev=50521&r1=50520&r2=50521&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp Thu May 1 01:39:12 2008
@@ -28,6 +28,7 @@
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Config/config.h"
using namespace llvm;
@@ -509,7 +510,7 @@
// See if we can get the length of the input string.
uint64_t Len = GetStringLength(Src);
- if (Len == 0) return false;
+ if (Len == 0) return 0;
--Len; // Unbias length.
// Handle the simple, do-nothing case: strcat(x, "") -> x
@@ -562,7 +563,7 @@
// a string literal. If so, we can constant fold.
std::string Str;
if (!GetConstantStringInfo(SrcStr, Str))
- return false;
+ return 0;
// strchr can find the nul character.
Str += '\0';
@@ -682,7 +683,7 @@
// See if we can get the length of the input string.
uint64_t Len = GetStringLength(Src);
- if (Len == 0) return false;
+ if (Len == 0) return 0;
// We have enough information to now generate the memcpy call to do the
// concatenation for us. Make a memcpy to copy the nul byte with align = 1.
@@ -737,7 +738,7 @@
// Make sure we have a constant length.
ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
- if (!LenC) return false;
+ if (!LenC) return 0;
uint64_t Len = LenC->getZExtValue();
if (Len == 0) // memcmp(s1,s2,0) -> 0
@@ -969,7 +970,7 @@
// Check for a fixed format string.
std::string FormatStr;
if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
- return false;
+ return 0;
// Empty format string -> noop.
if (FormatStr.empty()) // Tolerate printf's declared void.
@@ -1029,7 +1030,7 @@
// Check for a fixed format string.
std::string FormatStr;
if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
- return false;
+ return 0;
// If we just have a format string (nothing else crazy) transform it.
if (CI->getNumOperands() == 3) {
@@ -1052,10 +1053,14 @@
// Decode the second character of the format string.
if (FormatStr[1] == 'c') {
- // sprintf(dst, "%c", chr) --> *(i8*)dst = chr
+ // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
Value *V = B.CreateTrunc(CI->getOperand(3), Type::Int8Ty, "char");
- B.CreateStore(V, CastToCStr(CI->getOperand(1), B));
+ Value *Ptr = CastToCStr(CI->getOperand(1), B);
+ B.CreateStore(V, Ptr);
+ Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::Int32Ty, 1), "nul");
+ B.CreateStore(Constant::getNullValue(Type::Int8Ty), Ptr);
+
return ConstantInt::get(CI->getType(), 1);
}
@@ -1124,7 +1129,7 @@
// fputs(s,F) --> fwrite(s,1,strlen(s),F)
uint64_t Len = GetStringLength(CI->getOperand(1));
- if (!Len) return false;
+ if (!Len) return 0;
EmitFWrite(CI->getOperand(1), ConstantInt::get(TD->getIntPtrType(), Len-1),
CI->getOperand(2), B);
return CI; // Known to have no uses (see above).
@@ -1146,13 +1151,13 @@
// All the optimizations depend on the format string.
std::string FormatStr;
if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
- return false;
+ return 0;
// fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
if (CI->getNumOperands() == 3) {
for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
- return false; // We found a format specifier.
+ return 0; // We found a format specifier.
EmitFWrite(CI->getOperand(2), ConstantInt::get(TD->getIntPtrType(),
FormatStr.size()),
@@ -1317,6 +1322,9 @@
Value *Result = OMI->second->OptimizeCall(CI, TD, Builder);
if (Result == 0) continue;
+ DEBUG(DOUT << "SimplifyLibCalls simplified: " << *CI;
+ DOUT << " into: " << *Result << "\n");
+
// Something changed!
Changed = true;
++NumSimplified;
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