| Message ID | 1407185261-1799-1-git-send-email-andrey.krieger.utkin@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
From: Andrey Utkin <andrey.krieger.utkin@gmail.com> Date: Mon, 4 Aug 2014 23:47:41 +0300 > This commit is a guesswork, but it seems to make sense to drop this > break, as otherwise the following line is never executed and becomes > dead code. And that following line actually saves the result of > local calculation by the pointer given in function argument. So the > proposed change makes sense if this code in the whole makes sense (but I > am unable to analyze it in the whole). > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81641 > Reported-by: David Binderman <dcb314@hotmail.com> > Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> Yeah, not putting the condition code result into the register might cause problems :-) Thanks for catching this, applied and queued up for -stable. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 04.08.2014 22:47, schrieb Andrey Utkin: > This commit is a guesswork, but it seems to make sense to drop this > break, as otherwise the following line is never executed and becomes > dead code. And that following line actually saves the result of > local calculation by the pointer given in function argument. So the > proposed change makes sense if this code in the whole makes sense (but I > am unable to analyze it in the whole). > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81641 > Reported-by: David Binderman <dcb314@hotmail.com> > Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> > --- > arch/sparc/math-emu/math_32.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/sparc/math-emu/math_32.c b/arch/sparc/math-emu/math_32.c > index aa4d55b..5ce8f2f 100644 > --- a/arch/sparc/math-emu/math_32.c > +++ b/arch/sparc/math-emu/math_32.c > @@ -499,7 +499,7 @@ static int do_one_mathemu(u32 insn, unsigned long *pfsr, unsigned long *fregs) > case 0: fsr = *pfsr; > if (IR == -1) IR = 2; > /* fcc is always fcc0 */ The patch looks ok, but can somebody comment on this comment ? what "fcc" ? should it be a fsr ? > - fsr &= ~0xc00; fsr |= (IR << 10); break; > + fsr &= ~0xc00; fsr |= (IR << 10); nitpicking: fsr &= ~0xc00; fsr |= (IR << 10); It is better readable. re, wh > *pfsr = fsr; > break; > case 1: rd->s = IR; break; -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: walter harms <wharms@bfs.de> Date: Tue, 05 Aug 2014 09:11:52 +0200 > > > Am 04.08.2014 22:47, schrieb Andrey Utkin: >> This commit is a guesswork, but it seems to make sense to drop this >> break, as otherwise the following line is never executed and becomes >> dead code. And that following line actually saves the result of >> local calculation by the pointer given in function argument. So the >> proposed change makes sense if this code in the whole makes sense (but I >> am unable to analyze it in the whole). >> >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81641 >> Reported-by: David Binderman <dcb314@hotmail.com> >> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> >> --- >> arch/sparc/math-emu/math_32.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/sparc/math-emu/math_32.c b/arch/sparc/math-emu/math_32.c >> index aa4d55b..5ce8f2f 100644 >> --- a/arch/sparc/math-emu/math_32.c >> +++ b/arch/sparc/math-emu/math_32.c >> @@ -499,7 +499,7 @@ static int do_one_mathemu(u32 insn, unsigned long *pfsr, unsigned long *fregs) >> case 0: fsr = *pfsr; >> if (IR == -1) IR = 2; >> /* fcc is always fcc0 */ > > The patch looks ok, but can somebody comment on this comment ? > what "fcc" ? should it be a fsr ? It's the condition code field inside of the %fsr register. In 32-bit chips there is only one set of condition codes, whereas on 64-bit chips there are 4 sets referred to as fcc0, fcc1, fcc2, and fcc3. That's what this comment is talking about. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 05.08.2014 21:49, schrieb David Miller: > From: walter harms <wharms@bfs.de> > Date: Tue, 05 Aug 2014 09:11:52 +0200 > >> >> >> Am 04.08.2014 22:47, schrieb Andrey Utkin: >>> This commit is a guesswork, but it seems to make sense to drop this >>> break, as otherwise the following line is never executed and becomes >>> dead code. And that following line actually saves the result of >>> local calculation by the pointer given in function argument. So the >>> proposed change makes sense if this code in the whole makes sense (but I >>> am unable to analyze it in the whole). >>> >>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81641 >>> Reported-by: David Binderman <dcb314@hotmail.com> >>> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> >>> --- >>> arch/sparc/math-emu/math_32.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/arch/sparc/math-emu/math_32.c b/arch/sparc/math-emu/math_32.c >>> index aa4d55b..5ce8f2f 100644 >>> --- a/arch/sparc/math-emu/math_32.c >>> +++ b/arch/sparc/math-emu/math_32.c >>> @@ -499,7 +499,7 @@ static int do_one_mathemu(u32 insn, unsigned long *pfsr, unsigned long *fregs) >>> case 0: fsr = *pfsr; >>> if (IR == -1) IR = 2; >>> /* fcc is always fcc0 */ >> >> The patch looks ok, but can somebody comment on this comment ? >> what "fcc" ? should it be a fsr ? > > It's the condition code field inside of the %fsr register. > > In 32-bit chips there is only one set of condition codes, whereas > on 64-bit chips there are 4 sets referred to as fcc0, fcc1, fcc2, > and fcc3. > > That's what this comment is talking about. > thx for info, would you mind to add your explanation ? It is much mor helpful that the comment right now. re, wh -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/sparc/math-emu/math_32.c b/arch/sparc/math-emu/math_32.c index aa4d55b..5ce8f2f 100644 --- a/arch/sparc/math-emu/math_32.c +++ b/arch/sparc/math-emu/math_32.c @@ -499,7 +499,7 @@ static int do_one_mathemu(u32 insn, unsigned long *pfsr, unsigned long *fregs) case 0: fsr = *pfsr; if (IR == -1) IR = 2; /* fcc is always fcc0 */ - fsr &= ~0xc00; fsr |= (IR << 10); break; + fsr &= ~0xc00; fsr |= (IR << 10); *pfsr = fsr; break; case 1: rd->s = IR; break;
This commit is a guesswork, but it seems to make sense to drop this break, as otherwise the following line is never executed and becomes dead code. And that following line actually saves the result of local calculation by the pointer given in function argument. So the proposed change makes sense if this code in the whole makes sense (but I am unable to analyze it in the whole). Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81641 Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> --- arch/sparc/math-emu/math_32.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)