D/ldc
1
0
Fork 0
mirror of https://github.com/xomboverlord/ldc.git synced 2026-01-12 02:43:14 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

Remove calls to some runtime functions if their results are unused

Browse Source
This commit is contained in:
Frits van Bommel
2009-05-02 11:58:50 +02:00
parent cff0f1f446
commit 34955bcbf9
1 changed files with 31 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
gen/passes/SimplifyDRuntimeCalls.cpp
View File

@@ -145,6 +145,15 @@ struct VISIBILITY_HIDDEN ArrayCastLenOpt : public LibCallOptimization {
}
};
/// DeleteUnusedOpt - remove libcall if the return value is unused.
struct VISIBILITY_HIDDEN DeleteUnusedOpt : public LibCallOptimization {
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
if (CI->use_empty())
return CI;
return 0;
}
};
// TODO: More optimizations! :)
} // end anonymous namespace.
@@ -163,6 +172,9 @@ namespace {
ArraySetLengthOpt ArraySetLength;
ArrayCastLenOpt ArrayCastLen;
// GC allocations
DeleteUnusedOpt DeleteUnused;
public:
static char ID; // Pass identification
SimplifyDRuntimeCalls() : FunctionPass(&ID) {}
@@ -188,9 +200,28 @@ FunctionPass *createSimplifyDRuntimeCalls() {
/// Optimizations - Populate the Optimizations map with all the optimizations
/// we know.
void SimplifyDRuntimeCalls::InitOptimizations() {
// Some array-related optimizations
Optimizations["_d_arraysetlengthT"] = &ArraySetLength;
Optimizations["_d_arraysetlengthiT"] = &ArraySetLength;
Optimizations["_d_array_cast_len"] = &ArrayCastLen;
/* Delete calls to runtime functions which aren't needed if their result is
* unused. That comes down to functions that don't do anything but
* GC-allocate and initialize some memory.
* We don't need to do this for functions which are marked 'readnone' or
* 'readonly', since LLVM doesn't need our help figuring out when those can
* be deleted.
* (We can't mark allocating calls as readonly/readnone because they don't
* return the same pointer every time when called with the same arguments)
*/
Optimizations["_d_allocmemoryT"] = &DeleteUnused;
Optimizations["_d_newarrayT"] = &DeleteUnused;
Optimizations["_d_newarrayiT"] = &DeleteUnused;
Optimizations["_d_newarrayvT"] = &DeleteUnused;
Optimizations["_d_newarraymT"] = &DeleteUnused;
Optimizations["_d_newarraymiT"] = &DeleteUnused;
Optimizations["_d_newarraymvT"] = &DeleteUnused;
Optimizations["_d_allocclass"] = &DeleteUnused;
}