search for: hasstackfram

.... The problem occurs in function ARMFrameLowering.cpp:processFunctionBeforeCalleeSavedScan. There's a circular dependency in setting the variable BigStack and AFI->setHashStackFrame(true). The expression which initializes BigStack calls estimateRSSStackSizeLimit which in turn checks AFI->hasStackFrame(). Unfortunately setHasStackFrame(true) only gets called after BigStack is initialized. The specific issue this caused in my case was that BigStack got initialized as false because estimateRSSStackSizeLimit returned (1<<12)-1 instead of (1<<8)-1. The code thus never entered the if (Bi...

...Apart from that, looking at your patch and description I actually think that it is estimateRSStackSizeLimit that is wrong. It is performing a check for a Thumb2 addressing mode whether the target has a FP register. That's the main check - for some reason it is appending another check AFI->hasStackFrame() which seems wrong. The function should assume the function has a stack frame, because its entire function is to estimate its size! It looks like that check has been copy-pasted from elsewhere in the file. Anton, would you agree with this? I haven't looked at ARMFrameLowering before. Cheers...

Hello Alok, > I fixed this by performing the CanEliminateFrame and > RegInfo->cannotEliminateFrame checks before the call to > estimateRSSStackSizeLimit, since these values are available before BigStack > is initialized. Does that sound reasonable? I’ve attached a patch with my > change. Will you please provide a testcase which reproduces the problem? Thanks! -- With best