On Tue, Sep 16, 2014 at 5:53 PM, Akira Hatanaka <[email protected]> wrote:
> On Tue, Sep 16, 2014 at 5:12 PM, Eric Christopher <[email protected]> > wrote: > >> >> >> On Tue, Sep 16, 2014 at 4:00 PM, Akira Hatanaka <[email protected]> >> wrote: >> >>> On Tue, Sep 16, 2014 at 1:06 PM, Eric Christopher <[email protected]> >>> wrote: >>> >>>> You'll want to split out the new contraints for input size into a >>>> separate patch. (And just commit it). >>>> A small comment of why we're ignoring dependent types would be good. >>>> >>>> One question: Why not just add all of the contraints first rather than >>>> piecemeal as you get testcases? (Related to the comment above). >>>> >>>> >>> Just to make sure I'm not misunderstanding your question, are you >>> suggesting I use "=abcdSD" instead of "=a" in the test case and do the >>> check in one line? >>> >>> uint64_t val; >>> >>> __asm__ volatile("addl %1, %0" : "=abcdSD" (val) : "a" (msr)); // >>> expected-error {{invalid output size for constraint '=abcdSD'}} >>> >>> >>> Are you also suggesting that we should have clang print just the >>> constraints that are invalid in the error message? For example, if we added >>> "A" and use "=abcdSDA" instead, clang would remove "A", since it can be >>> bound to a 64-bit variable, and print "=abcdSD" or "abcdSD" instead? >>> >>> >>> >> No, I'm curious why you're adding S and D now, but not any other >> constraint that has a size associated with the register. >> >> > OK, I see. I just felt that S and D should be added too, since they are > single register constraints that have to be bound to variables smaller than > 64-bit, as constraints a-d are. > > I can probably add R, q, Q, to the switch-case statement too. Also, in my > next patch, I was going to add checks for constraints x and y. > > Should I add the all the constraints I mentioned above to > X86_32TargetInfo::validateInputSize or X86TargetInfo::validateInputSize > first and then add the checks for output constraints? > Seems like a reasonable way to go yes? -eric > > -eric >> >> >>> >>> Thanks! >>>> >>>> -eric >>>> >>>> On Fri Aug 29 2014 at 4:46:37 PM Akira Hatanaka <[email protected]> >>>> wrote: >>>> >>>>> Does the latest patch look fine? I am working on another patch which >>>>> fixes a similar bug and I need to commit this patch first. >>>>> >>>>> >>>>> On Thu, Aug 28, 2014 at 10:08 AM, Akira Hatanaka <[email protected]> >>>>> wrote: >>>>> >>>>>> Latest version of the patch is attached which fixes a couple of >>>>>> oversights. I had to add a line which checks whether Ty is a dependent >>>>>> type >>>>>> before getTypeSize is called. Also, in the test case, "=" was missing >>>>>> before constraint "a", so fixed that too. >>>>>> >>>>>> On Wed, Aug 27, 2014 at 3:22 PM, Reid Kleckner <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> New patch looks good to me. >>>>>>> >>>>>>> It sounds like we have two cases of size mismatch: >>>>>>> - The output operand lvalue is smaller than the constraint, meaning >>>>>>> the store will write out of bounds. Your patch adds this. >>>>>>> - The output operand lvalue is bigger than the constraint, meaning >>>>>>> the whole value won't be initialized. We currently warn here via >>>>>>> validateConstraintModifier. >>>>>>> >>>>>>> This code probably deserves some cleanup, but your patch is >>>>>>> consistent with what we do for input operands, so let's go with that. >>>>>>> >>>>>>> >>>>>> The reason llvm is crashing in the backend is that it's trying to use >>>>>> a 64-bit register in 32-bit mode. It's not because a store is writing out >>>>>> of bounds or there is a value left uninitialized. In the test case, if we >>>>>> declare the variable bound to constraint "=a" to be a unit32_t or an >>>>>> integer type that is smaller than 32-bit, clang compiles the program >>>>>> fine. >>>>>> >>>>>> >>>>>>> >>>>>>> On Wed, Aug 27, 2014 at 12:35 PM, Akira Hatanaka <[email protected] >>>>>>> > wrote: >>>>>>> >>>>>>>> The commit log in r166737 doesn't say much about why this is a >>>>>>>> warning instead of an error, but I know there are cases where warnings >>>>>>>> are >>>>>>>> needed. For example, clang has to issue warnings instead of errors for >>>>>>>> the >>>>>>>> inline-asm statements in the test case committed in r216260. If it's >>>>>>>> not >>>>>>>> desirable to change validateConstraintModifier, we can add a function >>>>>>>> which >>>>>>>> checks the output size that is similar to validateInputSize in r167717 >>>>>>>> (see >>>>>>>> attached patch), which was suggested in the post-commit review. >>>>>>>> >>>>>>>> >>>>>>>> http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20121112/067945.html >>>>>>>> >>>>>>>> I am not sure whether we can use fixit in this case. Fixit hints >>>>>>>> should be used only if we know the user's intent and it's very clear >>>>>>>> that >>>>>>>> applying the fixit hint is the right thing to do. Changing the type of >>>>>>>> variable "r" to a 32-bit int will avoid crashing, but it doesn't look >>>>>>>> like >>>>>>>> that's what the user wants. >>>>>>>> >>>>>>>> On Mon, Aug 25, 2014 at 6:20 PM, Reid Kleckner <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Can you investigate why we are warning in the first place? I think >>>>>>>>> we should either only warn or only error. Currently we have a warning >>>>>>>>> with >>>>>>>>> a fixit but we don't recover as though we had applied the fixit. If >>>>>>>>> we did >>>>>>>>> that, we would not crash. >>>>>>>>> >>>>>>>>> In addition to the Clang-side changes, LLVM should probably be >>>>>>>>> returning an error or reporting a fatal error instead of hitting >>>>>>>>> unreachable. >>>>>>>>> >>>>>>>>> >>>>>>>>> On Mon, Aug 25, 2014 at 2:10 PM, Akira Hatanaka < >>>>>>>>> [email protected]> wrote: >>>>>>>>> >>>>>>>>>> Rebased patches attached. >>>>>>>>>> >>>>>>>>>> I also made changes to the clang patch so that clang can >>>>>>>>>> error-out after a size mismatch is found as soon as >>>>>>>>>> possible.TargetInfo::validateConstraintModifier has an extra >>>>>>>>>> parameter >>>>>>>>>> IsError, which is set when it decides there is no point in continuing >>>>>>>>>> compilation and it should stop compilation immediately. The error >>>>>>>>>> message >>>>>>>>>> clang prints looks better than lllvm's message, but if it isn't >>>>>>>>>> right to >>>>>>>>>> change the warning to an error, then I guess we have to detect the >>>>>>>>>> error >>>>>>>>>> later just before isel, as is done in the llvm patch. >>>>>>>>>> >>>>>>>>>> On Wed, Jul 23, 2014 at 3:56 PM, Akira Hatanaka < >>>>>>>>>> [email protected]> wrote: >>>>>>>>>> >>>>>>>>>>> llvm should error-out when a 64-bit variable is bound to a >>>>>>>>>>> single register in x86 32-bit mode, but ToT clang/llvm fails to >>>>>>>>>>> detect this >>>>>>>>>>> error and continues compilation until it crashes in >>>>>>>>>>> type-legalization: >>>>>>>>>>> >>>>>>>>>>> $ llc test/CodeGen/X86/inline-asm-regsize.ll -O3 >>>>>>>>>>> -mtriple=i386-apple-darwin -o - >>>>>>>>>>> >>>>>>>>>>> inline-asm-regsize.ll -O3 -mtriple=i386-apple-darwin -o - >>>>>>>>>>> >>>>>>>>>>> .section __TEXT,__text,regular,pure_instructions >>>>>>>>>>> >>>>>>>>>>> ExpandIntegerResult #0: 0x7fa2d1041728: i64 = Register %RCX >>>>>>>>>>> [ID=0] >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Do not know how to expand the result of this operator! >>>>>>>>>>> >>>>>>>>>>> UNREACHABLE executed at >>>>>>>>>>> /Users/ahatanaka/projects/llvm/git/llvm3/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp:1116! >>>>>>>>>>> >>>>>>>>>>> The attached patch fixes llvm to error-out and print this error >>>>>>>>>>> message: >>>>>>>>>>> >>>>>>>>>>> error: Cannot bind a variable larger than 32-bit to a single >>>>>>>>>>> register in 32-bit mode >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> My initial solution was to have clang detect this error in >>>>>>>>>>> TargetInfo::validateConstraintModifier. However, the code in >>>>>>>>>>> SemaStmtAsm.cpp has to be changed to error-out instead of issuing a >>>>>>>>>>> warning, which I wasn't sure was the right thing to do. I am >>>>>>>>>>> attaching this >>>>>>>>>>> patch too in case someone has a suggestion or an opinion on it. >>>>>>>>>>> >>>>>>>>>>> <rdar://problem/17476970> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> cfe-commits mailing list >>>>>>>>>> [email protected] >>>>>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> >>>>> _______________________________________________ >>>>> cfe-commits mailing list >>>>> [email protected] >>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >>>>> >>>> >>> >> >
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