retitle 327351 libc rounding is broken on HPPA reassign 327351 libc6 tags 327351 +patch thanks
On Sep 9, 2005, at 3:25 PM, Wesley W. Terpstra wrote: On Sep 9, 2005, at 3:11 PM, Falk Hueffner wrote: __asm__ ("fstd %%fr0,0(%1)" : "=m" (*sw) : "r" (sw)); sw[0] &= ~FE_DOWNWARD; sw[0] |= round; __asm__ ("fldd 0(%0),%%fr0" : : "r" (sw));
This is not a bug in gcc. The second asm is not marked as reading *sw, so the store can be moved behind it, or omitted if it isn't needed elsewhere. If you access *sw, you need to tell gcc. So the bug is in whatever code contains this asm.
I don't know how the __asm__ directive works... "r" isn't for read? What exactly are you saying should be changed to fix it?
This code is from libc, so if I can verify what you say, I'll reassign the bug.
I tried using __asm__ ("fstd %%fr0,0(%1)" : "=m" (*sw) : "r" (sw)); sw[BYTE] &= ~FE_DOWNWARD; sw[BYTE] |= round; __asm__ ("fldd 0(%0), %%fr0" : : "r" (sw), "r" (*sw)); ... and it worked.
I don't understand why the *sw needs to be referenced, but you're right that this fixes the problem. I've attached a patch to fix this in libc.
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hppa-rounding.patch
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