aaron/ispc
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add support for broadcast(), rotate(), and shuffle() stdlib routines

Browse Source
This commit is contained in:
Matt Pharr
2011-06-27 17:31:44 -07:00
parent 36063bae79
commit 2709c354d7
15 changed files with 329 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
opt.cpp
View File

@@ -2116,11 +2116,12 @@ CreateLowerGatherScatterPass() {
// IsCompileTimeConstantPass
/** LLVM IR implementations of target-specific functions may include calls
to a function "bool __is_compile_time_constant_mask(mask type)"; this
allows them to have specialied code paths for where the mask is known
at compile time but not incurring the cost of a MOVMSK call at runtime
to compute its value in cases where the mask value isn't known until
runtime.
to the functions "bool __is_compile_time_constant_mask(mask type)" and
"bool __is_compile_time_constant_int32(i32)"; these allow them to have
specialied code paths for where the corresponding value is known at
compile time. For masks, for example, this allows them to not incur
the cost of a MOVMSK call at runtime to compute its value in cases
where the mask value isn't known until runtime.
This pass resolves these calls into either 'true' or 'false' values so
that later optimization passes can operate with these as constants.
@@ -2148,17 +2149,17 @@ llvm::RegisterPass<IsCompileTimeConstantPass>
bool
IsCompileTimeConstantPass::runOnBasicBlock(llvm::BasicBlock &bb) {
llvm::Function *func = m->module->getFunction("__is_compile_time_constant_mask");
if (!func)
return false;
llvm::Function *maskFunc = m->module->getFunction("__is_compile_time_constant_mask");
llvm::Function *int32Func = m->module->getFunction("__is_compile_time_constant_int32");
bool modifiedAny = false;
restart:
for (llvm::BasicBlock::iterator i = bb.begin(), e = bb.end(); i != e; ++i) {
// Iterate through the instructions looking for calls to
// __is_compile_time_constant_mask().
// Iterate through the instructions looking for calls to the
// __is_compile_time_constant_*() functions
llvm::CallInst *callInst = llvm::dyn_cast<llvm::CallInst>(&*i);
if (!callInst || callInst->getCalledFunction() != func)
if (!callInst || (callInst->getCalledFunction() != maskFunc &&
callInst->getCalledFunction() != int32Func))
continue;
// This optimization pass can be disabled with the (poorly named)
@@ -2171,8 +2172,8 @@ IsCompileTimeConstantPass::runOnBasicBlock(llvm::BasicBlock &bb) {
// Is it a constant? Bingo, turn the call's value into a constant
// true value.
llvm::Value *mask = callInst->getArgOperand(0);
if (llvm::isa<llvm::Constant>(mask)) {
llvm::Value *operand = callInst->getArgOperand(0);
if (llvm::isa<llvm::Constant>(operand)) {
llvm::ReplaceInstWithValue(i->getParent()->getInstList(), i, LLVMTrue);
modifiedAny = true;
goto restart;