[llvm] r176066 - [fast-isel] Make sure the FastLowerArguments function checks to make sure the

[Chad Rosier]

On Feb 26, 2013, at 12:19 PM, David Blaikie <dblaikie at gmail.com> wrote:

> On Tue, Feb 26, 2013 at 12:03 PM, Chad Rosier <mcrosier at apple.com> wrote:
>> 
>> On Feb 26, 2013, at 11:51 AM, David Blaikie <dblaikie at gmail.com> wrote:
>> 
>> On Tue, Feb 26, 2013 at 11:48 AM, Chad Rosier <mcrosier at apple.com> wrote:
>> 
>> 
>> On Feb 25, 2013, at 6:33 PM, David Blaikie <dblaikie at gmail.com> wrote:
>> 
>> 
>> 
>> 
>> On Mon, Feb 25, 2013 at 5:05 PM, Chad Rosier <mcrosier at apple.com> wrote:
>> 
>> 
>> Author: mcrosier
>> Date: Mon Feb 25 19:05:31 2013
>> New Revision: 176066
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=176066&view=rev
>> Log:
>> [fast-isel] Make sure the FastLowerArguments function checks to make sure
>> the
>> arguments type is a simple type.
>> rdar://13290455
>> 
>> 
>> 
>> Test case?
>> 
>> 
>> David,
>> I'm not aware of an easy way to test this.
>> 
>> ; RUN: not llc < %s -fast-isel -fast-isel-abort -fast-isel-abort-args
>> -verify-machineinstrs -mtriple=x86_64-apple-darwin10
>> 
>> ; Abort because we don't know how to handle non-simple type i31.
>> define i31 @t1(i31 %a, i31 %b, i31 %c) {
>> entry:
>> %add = add nsw i31 %b, %a
>> %add1 = add nsw i31 %add, %c
>> ret i31 %add1
>> }
>> 
>> The above test case will exercise the issue, but results in llc aborting and
>> the 'not' on the run line doesn't have the correct effect.
>> 
>> 
>> I'm by no means especially familiar with the backend, just looking at
>> the change it seemed like something that I would expect to have an
>> easily observable effect.
>> 
>> 
>> I assume the -fast-isel-abort-args/-fast-isel-abort is what's meant to
>> cause the abort if fast isel can't handle something?
> 
> That's usually totally fine by me - you can include "Requires:
> Asserts" so we don't bother running the test on non-asserts build
> where it wouldn't catch the regression anyway.

Done so in r176119.  Thanks, David.

> 
> - David
> 
>> 
>> 
>> Correct.
>> 
>> Do we produce the
>> same code before/after your change, but the only issue is that
>> previously we would do it with fast isel & now we don't?
>> 
>> 
>> No, this was causing an assert when ArgVT.getSimpleVT() was called.
>> 
>> What was the
>> correctness problem (why make any change at all) then? If there was a
>> correctness problem, can't we just test that in the actually assembly
>> output rather than testing whether fast isel aborts?
>> 
>> 
>> The issue was a compiler assertion.
>> 
>> I could just remove the -fast-isel-abort-args flag to avoid causing the
>> abort.  Would that suffice as a test?
>> I could comment that this previously caused an assert.
>> 
>> Chad
>> 
>> - David
>> 
>> 
>> Chad
>> 
>> 
>> 
>> 
>> Modified:
>>   llvm/trunk/lib/Target/ARM/ARMFastISel.cpp
>>   llvm/trunk/lib/Target/X86/X86FastISel.cpp
>> 
>> Modified: llvm/trunk/lib/Target/ARM/ARMFastISel.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMFastISel.cpp?rev=176066&r1=176065&r2=176066&view=diff
>> 
>> ==============================================================================
>> --- llvm/trunk/lib/Target/ARM/ARMFastISel.cpp (original)
>> +++ llvm/trunk/lib/Target/ARM/ARMFastISel.cpp Mon Feb 25 19:05:31 2013
>> @@ -2922,6 +2922,7 @@ bool ARMFastISel::FastLowerArguments() {
>>      return false;
>> 
>>    EVT ArgVT = TLI.getValueType(ArgTy);
>> +    if (!ArgVT.isSimple()) return false;
>>    switch (ArgVT.getSimpleVT().SimpleTy) {
>>    case MVT::i8:
>>    case MVT::i16:
>> 
>> Modified: llvm/trunk/lib/Target/X86/X86FastISel.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FastISel.cpp?rev=176066&r1=176065&r2=176066&view=diff
>> 
>> ==============================================================================
>> --- llvm/trunk/lib/Target/X86/X86FastISel.cpp (original)
>> +++ llvm/trunk/lib/Target/X86/X86FastISel.cpp Mon Feb 25 19:05:31 2013
>> @@ -1555,6 +1555,7 @@ bool X86FastISel::FastLowerArguments() {
>>      return false;
>> 
>>    EVT ArgVT = TLI.getValueType(ArgTy);
>> +    if (!ArgVT.isSimple()) return false;
>>    switch (ArgVT.getSimpleVT().SimpleTy) {
>>    case MVT::i32:
>>    case MVT::i64:
>> 
>> 
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20130226/cc77e64e/attachment.html>