https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115823
Bug ID: 115823
Summary: Wrong expansion of isnormal optab
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: modula2
Assignee: gaius at gcc dot gnu.org
Reporter: stefansf at gcc dot gnu.org
Target Milestone: ---
Implementing isnormal optab for s390 results in
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -O
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -O -g
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -O3
-fomit-frame-pointer
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -O3
-fomit-frame-pointer -finline-functions
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -Os
FAIL: gm2/builtins/run/pass/testisnormal.mod compilation, -g
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -O (link
failed)
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -O -g (link
failed)
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -O3
-fomit-frame-pointer (link failed)
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -O3
-fomit-frame-pointer -finline-functions (link failed)
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -Os (link
failed)
UNRESOLVED: gm2/builtins/run/pass/testisnormal.mod execution, -g (link
failed)
All tests output
/usr/bin/ld: /tmp/ccFZtxN6.o: in function `test':
testisnormal.mod:(.text+0x2d4): undefined reference to `__builtin_isnormal'
collect2: error: ld returned 1 exit status
In math.h we have
# define isnormal(x) __builtin_isnormal (x)
which means for C code in expand_builtin
if (!optimize
&& !called_as_built_in (fndecl)
&& fcode != BUILT_IN_FORK
&& fcode != BUILT_IN_EXECL
&& fcode != BUILT_IN_EXECV
&& fcode != BUILT_IN_EXECLP
&& fcode != BUILT_IN_EXECLE
&& fcode != BUILT_IN_EXECVP
&& fcode != BUILT_IN_EXECVE
&& fcode != BUILT_IN_CLEAR_CACHE
&& !ALLOCA_FUNCTION_CODE_P (fcode)
&& fcode != BUILT_IN_FREE
&& (fcode != BUILT_IN_MEMSET
|| !(flag_inline_stringops & ILSOP_MEMSET))
&& (fcode != BUILT_IN_MEMCPY
|| !(flag_inline_stringops & ILSOP_MEMCPY))
&& (fcode != BUILT_IN_MEMMOVE
|| !(flag_inline_stringops & ILSOP_MEMMOVE))
&& (fcode != BUILT_IN_MEMCMP
|| !(flag_inline_stringops & ILSOP_MEMCMP)))
return expand_call (exp, target, ignore);
`called_as_built_in (fndecl)` is always true whereas for gm2 it evaluates to
false due to the call side being
isnormal (1.0e+0)
However, in rtx_for_function_call the symbol reference
funexp = XEXP (DECL_RTL (fndecl), 0);
is actually __builtin_isnormal which leads to a linker error.
Out of curiosity, the test output indicates that this error also happens e.g.
for -O3. However, looking into the logs, those tests where never executed with
-O3. Kinda surprised me.
