Hi,
Working on private backend, based on llvm-3.7
Inside lib/Transforms/InstCombine/InstCombineCompares.cpp there is
attempt to optimize fabs:
if (F->getIntrinsicID() == Intrinsic::fabs ||
...
switch (I.getPredicate()) {
...
case FCmpInst::FCMP_OGT:
return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0),
RHSC);
But
CI->getArgOperand(0) returns operand with type (double*) rather then
double, because in our ABI doubles are passed via memory.
Next assertion fires inside FCmpInst ctor:
llvm::FCmpInst::FCmpInst(llvm::CmpInst::Predicate, llvm::Value*,
llvm::Value*, const llvm::Twine&): Assertion `getOperand(0)->getType()
== getOperand(1)->getType() && "Both operands to FCmp
instruction are
not of the same type!"' failed.
I think, here required some check that CI->getArgOperand returns
correct value before trying to optimize.
What would you advise?
---
With best regards, Konstantin
On 2/16/2016 8:44 AM, Konstantin Vladimirov via llvm-dev wrote:> > CI->getArgOperand(0) returns operand with type (double*) rather then > double, because in our ABI doubles are passed via memory.The LLVM intrinsics in the LLVM IR must conform to whatever the IR's requirements are. That means that even in the case of your backend, the arguments to the intrinsic must be doubles, not their addresses. You can convert the intrinsics to function calls, together with the call frame set up, etc. during instruction selection. Check setLibcallName, setLibcallCallingConv (and related functions) in include/llvm/Target/TargetLowering.h. The Libcall enum is defined in include/llvm/CodeGen/RuntimeLibcalls.h -Krzysztof -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
Hi, Thanks a lot for correction, I rewritten and debugged some code and now everything works: I really should process calling convention in argument lowering inside llvm backend, not in classifyArgumentType inside ABIInfo inherited class in clang codegen. This is not at all obvious: correcting arguments at early stages looks simpler, but leads to tricky problems with high-level IR optimizations. --- With best regards, Konstantin On Tue, Feb 16, 2016 at 6:07 PM, Krzysztof Parzyszek via llvm-dev <llvm-dev at lists.llvm.org> wrote:> On 2/16/2016 8:44 AM, Konstantin Vladimirov via llvm-dev wrote: >> >> >> CI->getArgOperand(0) returns operand with type (double*) rather then >> double, because in our ABI doubles are passed via memory. > > > The LLVM intrinsics in the LLVM IR must conform to whatever the IR's > requirements are. That means that even in the case of your backend, the > arguments to the intrinsic must be doubles, not their addresses. You can > convert the intrinsics to function calls, together with the call frame set > up, etc. during instruction selection. > > Check setLibcallName, setLibcallCallingConv (and related functions) in > include/llvm/Target/TargetLowering.h. The Libcall enum is defined in > include/llvm/CodeGen/RuntimeLibcalls.h > > -Krzysztof > > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by > The Linux Foundation > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev