* [9fans] 6c bug?
@ 2012-02-28 4:40 erik quanstrom
2012-02-28 7:14 ` Bruce Ellis
[not found] ` <CAJQxxw=AN0dUGdu_sbdOc2Vkew3BXWPhvTOAxKKLgjHGxpxVjw@mail.gmail.c>
0 siblings, 2 replies; 5+ messages in thread
From: erik quanstrom @ 2012-02-28 4:40 UTC (permalink / raw)
To: 9fans
for p = uchar*, Nbus==256,
if((uint)p[1] >= Nbus){
generates
warning: ./mp.c:212 useless or misleading comparison: UCHAR >= 0x100
i'm pretty sure that 6c is incorrectly issuing the diagnostic before
applying the cast. (the cast is there to shut the compiler up.)
- erik
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [9fans] 6c bug? 2012-02-28 4:40 [9fans] 6c bug? erik quanstrom @ 2012-02-28 7:14 ` Bruce Ellis [not found] ` <CAJQxxw=AN0dUGdu_sbdOc2Vkew3BXWPhvTOAxKKLgjHGxpxVjw@mail.gmail.c> 1 sibling, 0 replies; 5+ messages in thread From: Bruce Ellis @ 2012-02-28 7:14 UTC (permalink / raw) To: Fans of the OS Plan 9 from Bell Labs what values of p[1] do you expect the test to be of use? On 28 February 2012 15:40, erik quanstrom <quanstro@quanstro.net> wrote: > for p = uchar*, Nbus==256, > > if((uint)p[1] >= Nbus){ > > generates > > warning: ./mp.c:212 useless or misleading comparison: UCHAR >= 0x100 > > i'm pretty sure that 6c is incorrectly issuing the diagnostic before > applying the cast. (the cast is there to shut the compiler up.) > > - erik > -- Don't meddle in the mouth -- MVS (0416935147, +1-513-3BRUCEE) ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <CAJQxxw=AN0dUGdu_sbdOc2Vkew3BXWPhvTOAxKKLgjHGxpxVjw@mail.gmail.c>]
* Re: [9fans] 6c bug? [not found] ` <CAJQxxw=AN0dUGdu_sbdOc2Vkew3BXWPhvTOAxKKLgjHGxpxVjw@mail.gmail.c> @ 2012-02-28 7:20 ` erik quanstrom 2012-02-28 9:22 ` Bruce Ellis [not found] ` <CAJQxxwka-EGOgyTV-xBB1YOWTXLzyL=qtRWDkfz0NmD82koFpQ@mail.gmail.c> 0 siblings, 2 replies; 5+ messages in thread From: erik quanstrom @ 2012-02-28 7:20 UTC (permalink / raw) To: 9fans On Tue Feb 28 02:16:04 EST 2012, bruce.ellis@gmail.com wrote: > what values of p[1] do you expect the test to be of use? > > On 28 February 2012 15:40, erik quanstrom <quanstro@quanstro.net> wrote: > > for p = uchar*, Nbus==256, > > > > if((uint)p[1] >= Nbus){ > > > > generates > > > > warning: ./mp.c:212 useless or misleading comparison: UCHAR >= 0x100 > > > > i'm pretty sure that 6c is incorrectly issuing the diagnostic before > > applying the cast. (the cast is there to shut the compiler up.) it is not a given that Nbus >= 255. - erik ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [9fans] 6c bug? 2012-02-28 7:20 ` erik quanstrom @ 2012-02-28 9:22 ` Bruce Ellis [not found] ` <CAJQxxwka-EGOgyTV-xBB1YOWTXLzyL=qtRWDkfz0NmD82koFpQ@mail.gmail.c> 1 sibling, 0 replies; 5+ messages in thread From: Bruce Ellis @ 2012-02-28 9:22 UTC (permalink / raw) To: Fans of the OS Plan 9 from Bell Labs for the example you gave the diagnostic is correct. On 28 February 2012 18:20, erik quanstrom <quanstro@quanstro.net> wrote: > On Tue Feb 28 02:16:04 EST 2012, bruce.ellis@gmail.com wrote: >> what values of p[1] do you expect the test to be of use? >> >> On 28 February 2012 15:40, erik quanstrom <quanstro@quanstro.net> wrote: >> > for p = uchar*, Nbus==256, >> > >> > if((uint)p[1] >= Nbus){ >> > >> > generates >> > >> > warning: ./mp.c:212 useless or misleading comparison: UCHAR >= 0x100 >> > >> > i'm pretty sure that 6c is incorrectly issuing the diagnostic before >> > applying the cast. (the cast is there to shut the compiler up.) > > it is not a given that Nbus >= 255. > > - erik > -- Don't meddle in the mouth -- MVS (0416935147, +1-513-3BRUCEE) ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <CAJQxxwka-EGOgyTV-xBB1YOWTXLzyL=qtRWDkfz0NmD82koFpQ@mail.gmail.c>]
* Re: [9fans] 6c bug? [not found] ` <CAJQxxwka-EGOgyTV-xBB1YOWTXLzyL=qtRWDkfz0NmD82koFpQ@mail.gmail.c> @ 2012-02-28 18:37 ` erik quanstrom 0 siblings, 0 replies; 5+ messages in thread From: erik quanstrom @ 2012-02-28 18:37 UTC (permalink / raw) To: 9fans On Tue Feb 28 04:23:56 EST 2012, bruce.ellis@gmail.com wrote: > for the example you gave the diagnostic is correct. pffft. you're right. - erik ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-02-28 18:37 UTC | newest]
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2012-02-28 4:40 [9fans] 6c bug? erik quanstrom
2012-02-28 7:14 ` Bruce Ellis
[not found] ` <CAJQxxw=AN0dUGdu_sbdOc2Vkew3BXWPhvTOAxKKLgjHGxpxVjw@mail.gmail.c>
2012-02-28 7:20 ` erik quanstrom
2012-02-28 9:22 ` Bruce Ellis
[not found] ` <CAJQxxwka-EGOgyTV-xBB1YOWTXLzyL=qtRWDkfz0NmD82koFpQ@mail.gmail.c>
2012-02-28 18:37 ` erik quanstrom
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