| Summary: | math/test-ildouble-fma, math/test-ldouble-fma test suite failures on ppc64le | ||
|---|---|---|---|
| Product: | glibc | Reporter: | Florian Weimer <fweimer> |
| Component: | math | Assignee: | Not yet assigned to anyone <unassigned> |
| Status: | RESOLVED INVALID | ||
| Severity: | normal | CC: | tuliom |
| Priority: | P2 | Flags: | fweimer:
security-
|
| Version: | 2.28 | ||
| Target Milestone: | --- | ||
| See Also: | https://sourceware.org/bugzilla/show_bug.cgi?id=23272 | ||
| Host: | Target: | ppc64le | |
| Build: | Last reconfirmed: | ||
IBM long double only supports default rounding. Looks like there are some XFAIL_ROUNDING_IBM128_LIBGCC missing. I didn't see any response to my review questions at https://sourceware.org/ml/libc-alpha/2018-06/msg00375.html following Tulio's patch. This is an automated email from the git hooks/post-receive script. It was
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- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=f346b5b38ce83ebc832590273e134c53adc06f21
commit f346b5b38ce83ebc832590273e134c53adc06f21
Author: Joseph Myers <joseph@codesourcery.com>
Date: Tue Oct 2 17:17:15 2018 +0000
Add more fma tests.
In my review
<https://sourceware.org/ml/libc-alpha/2018-06/msg00375.html> of a
patch for bug 23584, I expressed concern that the proposed changes
didn't deal with certain cases similar to the ones in the bug but
where test coverage was missing.
This patch adds such tests of fma (Inf, finite, finite) and fma
(finite, Inf, finite) to libm-test-fma.inc. It does *not* do anything
to fix the bug, simply adds test coverage to provide stronger evidence
of whether any proposed revised fix does address the cases I was
concerned with.
Tested for x86_64 and x86.
* math/libm-test-fma.inc (fma_test_data): Add more tests.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 4 +
math/libm-test-fma.inc | 193 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 197 insertions(+), 0 deletions(-)
I've confirmed these failures are caused by spurious overflows in libgcc. Commit ecdacd34a2ac3b6d5a529ff218b29261d9d98a7a is now XFAIL'ing these entries. I'm closing this now. Reference: https://www.sourceware.org/ml/libc-alpha/2019-01/msg00304.html |
We see this failure: =====FAIL: math/test-ildouble-fma.out===== testing long double (inline functions) Failure: Test: fma_downward (inf, inf, -max_value) Result: is: qNaN should be: inf inf Failure: Test: fma_downward (-inf, -inf, -max_value) Result: is: qNaN should be: inf inf Failure: Test: fma_upward (inf, -inf, max_value) Result: is: qNaN should be: -inf -inf Failure: Test: fma_upward (-inf, inf, max_value) Result: is: qNaN should be: -inf -inf Test suite completed: 1458 test cases plus 0 tests for exception flags and 0 tests for errno executed. 4 errors occurred. =====FAIL: math/test-ldouble-fma.out===== testing long double (without inline functions) Failure: fma_downward (inf, inf, -max_value): Exception "Invalid operation" set Failure: fma_downward (inf, inf, -max_value): Exception "Overflow" set Failure: Test: fma_downward (inf, inf, -max_value) Result: is: qNaN should be: inf inf Failure: fma_downward (inf, -inf, -max_value): Exception "Overflow" set Failure: fma_downward (-inf, inf, -max_value): Exception "Overflow" set Failure: fma_downward (-inf, -inf, -max_value): Exception "Invalid operation" set Failure: fma_downward (-inf, -inf, -max_value): Exception "Overflow" set Failure: Test: fma_downward (-inf, -inf, -max_value) Result: is: qNaN should be: inf inf Failure: fma_upward (inf, inf, max_value): Exception "Overflow" set Failure: fma_upward (inf, -inf, max_value): Exception "Invalid operation" set Failure: fma_upward (inf, -inf, max_value): Exception "Overflow" set Failure: Test: fma_upward (inf, -inf, max_value) Result: is: qNaN should be: -inf -inf Failure: fma_upward (-inf, inf, max_value): Exception "Invalid operation" set Failure: fma_upward (-inf, inf, max_value): Exception "Overflow" set Failure: Test: fma_upward (-inf, inf, max_value) Result: is: qNaN should be: -inf -inf Failure: fma_upward (-inf, -inf, max_value): Exception "Overflow" set Test suite completed: 1458 test cases plus 1454 tests for exception flags and 1454 tests for errno executed. 16 errors occurred. glibc was compiled with: gcc version 8.2.1 20180726 (Red Hat 8.2.1-1) (GCC) After fesetround (3), I see this call: Breakpoint 1, 0x00007ffff7e73718 in __fmal (x=inf, y=inf, z=-1.79769313486231580793728971405301e+308) at ../sysdeps/ieee754/ldbl-128ibm/s_fmal.c:128 the true branch of this if statement: 155 /* If x or y or z is Inf/NaN, or if x * y is zero, compute as x * y 156 + z. */ 157 if (xexp == 0x7ff || yexp == 0x7ff || zexp == 0x7ff 158 || x == 0 || y == 0) 159 return (x * y) + z; Which is implemented as: => 0x00007ffff7e739f0 <+736>: fmr f3,f28 0x00007ffff7e739f4 <+740>: fmr f4,f29 0x00007ffff7e739f8 <+744>: fmr f1,f12 0x00007ffff7e739fc <+748>: fmr f2,f13 0x00007ffff7e73a00 <+752>: bl 0x7ffff7ee4db8 <__gcc_qmul+8> 0x00007ffff7e73a04 <+756>: nop 0x00007ffff7e73a08 <+760>: fmr f3,f30 0x00007ffff7e73a0c <+764>: fmr f4,f31 0x00007ffff7e73a10 <+768>: bl 0x7ffff7ee4c98 <__gcc_qadd+8> 0x00007ffff7e73a14 <+772>: nop 0x00007ffff7e73a18 <+776>: fmr f31,f2 0x00007ffff7e73a1c <+780>: fmr f30,f1 0x00007ffff7e73a20 <+784>: ld r9,216(r1) 0x00007ffff7e73a24 <+788>: ld r10,-28688(r13) 0x00007ffff7e73a28 <+792>: xor. r9,r9,r10 0x00007ffff7e73a2c <+796>: li r10,0 0x00007ffff7e73a30 <+800>: fmr f1,f30 0x00007ffff7e73a34 <+804>: fmr f2,f31 Our __gcc_qmul looks like this (I think): (gdb) disassemble 0x7ffff7ee4db8 Dump of assembler code for function __gcc_qmul: 0x00007ffff7ee4db0 <+0>: addis r2,r12,9 0x00007ffff7ee4db4 <+4>: addi r2,r2,10320 0x00007ffff7ee4db8 <+8>: fmul f0,f1,f3 0x00007ffff7ee4dbc <+12>: xxlxor vs12,vs12,vs12 0x00007ffff7ee4dc0 <+16>: fcmpu cr7,f0,f12 0x00007ffff7ee4dc4 <+20>: beq cr7,0x7ffff7ee4e10 <__gcc_qmul+96> 0x00007ffff7ee4dc8 <+24>: ld r9,-32520(r2) 0x00007ffff7ee4dcc <+28>: fabs f12,f0 0x00007ffff7ee4dd0 <+32>: lfd f10,0(r9) 0x00007ffff7ee4dd4 <+36>: fcmpu cr7,f12,f10 0x00007ffff7ee4dd8 <+40>: bge cr7,0x7ffff7ee4e10 <__gcc_qmul+96> 0x00007ffff7ee4ddc <+44>: fmul f2,f3,f2 0x00007ffff7ee4de0 <+48>: fmsub f3,f1,f3,f0 0x00007ffff7ee4de4 <+52>: fmadd f1,f1,f4,f2 0x00007ffff7ee4de8 <+56>: fadd f1,f1,f3 0x00007ffff7ee4dec <+60>: fadd f11,f0,f1 0x00007ffff7ee4df0 <+64>: fabs f12,f11 0x00007ffff7ee4df4 <+68>: fcmpu cr7,f12,f10 0x00007ffff7ee4df8 <+72>: bge cr7,0x7ffff7ee4e20 <__gcc_qmul+112> 0x00007ffff7ee4dfc <+76>: fsub f0,f0,f11 0x00007ffff7ee4e00 <+80>: fadd f0,f0,f1 0x00007ffff7ee4e04 <+84>: fmr f1,f11 0x00007ffff7ee4e08 <+88>: fmr f2,f0 0x00007ffff7ee4e0c <+92>: blr 0x00007ffff7ee4e10 <+96>: fmr f1,f0 0x00007ffff7ee4e14 <+100>: xxlxor vs2,vs2,vs2 0x00007ffff7ee4e18 <+104>: blr 0x00007ffff7ee4e1c <+108>: ori r2,r2,0 0x00007ffff7ee4e20 <+112>: fmr f1,f11 0x00007ffff7ee4e24 <+116>: xxlxor vs2,vs2,vs2 0x00007ffff7ee4e28 <+120>: blr 0x00007ffff7ee4e2c <+124>: .long 0x0 0x00007ffff7ee4e30 <+128>: .long 0x0 0x00007ffff7ee4e34 <+132>: .long 0x0 End of assembler dump. __gcc_qadd is this: (gdb) disassemble 0x7ffff7ee4c98 Dump of assembler code for function __gcc_qadd: 0x00007ffff7ee4c90 <+0>: addis r2,r12,9 0x00007ffff7ee4c94 <+4>: addi r2,r2,10608 0x00007ffff7ee4c98 <+8>: fadd f12,f1,f3 0x00007ffff7ee4c9c <+12>: ld r9,-32520(r2) 0x00007ffff7ee4ca0 <+16>: lfd f10,0(r9) 0x00007ffff7ee4ca4 <+20>: fabs f11,f12 0x00007ffff7ee4ca8 <+24>: fcmpu cr7,f11,f10 0x00007ffff7ee4cac <+28>: bge cr7,0x7ffff7ee4d10 <__gcc_qadd+128> 0x00007ffff7ee4cb0 <+32>: fsub f0,f1,f12 0x00007ffff7ee4cb4 <+36>: xxlxor vs11,vs11,vs11 0x00007ffff7ee4cb8 <+40>: fadd f9,f12,f0 0x00007ffff7ee4cbc <+44>: fadd f3,f3,f0 0x00007ffff7ee4cc0 <+48>: fsub f1,f1,f9 0x00007ffff7ee4cc4 <+52>: fadd f1,f1,f3 0x00007ffff7ee4cc8 <+56>: fadd f1,f1,f2 0x00007ffff7ee4ccc <+60>: fadd f4,f1,f4 0x00007ffff7ee4cd0 <+64>: fcmpu cr7,f4,f11 0x00007ffff7ee4cd4 <+68>: beq cr7,0x7ffff7ee4d00 <__gcc_qadd+112> 0x00007ffff7ee4cd8 <+72>: fadd f11,f12,f4 0x00007ffff7ee4cdc <+76>: fabs f0,f11 0x00007ffff7ee4ce0 <+80>: fcmpu cr7,f0,f10 0x00007ffff7ee4ce4 <+84>: bge cr7,0x7ffff7ee4d60 <__gcc_qadd+208> 0x00007ffff7ee4ce8 <+88>: fsub f1,f12,f11 0x00007ffff7ee4cec <+92>: fadd f4,f1,f4 0x00007ffff7ee4cf0 <+96>: fmr f1,f11 0x00007ffff7ee4cf4 <+100>: fmr f2,f4 0x00007ffff7ee4cf8 <+104>: blr 0x00007ffff7ee4cfc <+108>: ori r2,r2,0 0x00007ffff7ee4d00 <+112>: fmr f1,f12 0x00007ffff7ee4d04 <+116>: xxlxor vs2,vs2,vs2 0x00007ffff7ee4d08 <+120>: blr 0x00007ffff7ee4d0c <+124>: ori r2,r2,0 0x00007ffff7ee4d10 <+128>: ld r9,-32512(r2) 0x00007ffff7ee4d14 <+132>: lfd f0,0(r9) 0x00007ffff7ee4d18 <+136>: fcmpu cr7,f11,f0 0x00007ffff7ee4d1c <+140>: ble cr7,0x7ffff7ee4d00 <__gcc_qadd+112> 0x00007ffff7ee4d20 <+144>: fadd f4,f4,f2 0x00007ffff7ee4d24 <+148>: fadd f11,f4,f3 0x00007ffff7ee4d28 <+152>: fadd f11,f11,f1 0x00007ffff7ee4d2c <+156>: fabs f0,f11 0x00007ffff7ee4d30 <+160>: fcmpu cr7,f0,f10 0x00007ffff7ee4d34 <+164>: bge cr7,0x7ffff7ee4d60 <__gcc_qadd+208> 0x00007ffff7ee4d38 <+168>: fabs f0,f1 0x00007ffff7ee4d3c <+172>: fabs f12,f3 0x00007ffff7ee4d40 <+176>: fcmpu cr7,f0,f12 0x00007ffff7ee4d44 <+180>: ble cr7,0x7ffff7ee4d70 <__gcc_qadd+224> 0x00007ffff7ee4d48 <+184>: fsub f0,f1,f11 0x00007ffff7ee4d4c <+188>: fadd f1,f0,f3 0x00007ffff7ee4d50 <+192>: fadd f4,f1,f4 0x00007ffff7ee4d54 <+196>: b 0x7ffff7ee4cf0 <__gcc_qadd+96> 0x00007ffff7ee4d58 <+200>: nop 0x00007ffff7ee4d5c <+204>: ori r2,r2,0 0x00007ffff7ee4d60 <+208>: fmr f1,f11 0x00007ffff7ee4d64 <+212>: xxlxor vs2,vs2,vs2 0x00007ffff7ee4d68 <+216>: blr 0x00007ffff7ee4d6c <+220>: ori r2,r2,0 0x00007ffff7ee4d70 <+224>: fsub f3,f3,f11 0x00007ffff7ee4d74 <+228>: fadd f3,f3,f1 0x00007ffff7ee4d78 <+232>: fadd f4,f3,f4 0x00007ffff7ee4d7c <+236>: b 0x7ffff7ee4cf0 <__gcc_qadd+96> 0x00007ffff7ee4d80 <+240>: .long 0x0 0x00007ffff7ee4d84 <+244>: .long 0x0 0x00007ffff7ee4d88 <+248>: .long 0x0 End of assembler dump. I'm not sure if this is a bug in the fmal code or the __gcc_qmul/__gcc_qadd functions.