[Bug c/34589] New: noreturn calls: gcc generates call instead of jump
vyzo at media dot mit dot edu
gcc-bugzilla@gcc.gnu.org
Wed Dec 26 06:56:00 GMT 2007
When noreturn functions call other noreturn functions, gcc still generates a
call instruction instead of a jump instruction. This result in slightly slower
execution and a small space leak on the stack, which affects higher level
language compilers that target gnu C as intermediate language and use CPS with
cheney on stack.
Example:
see attached whycall.c and whycall.s is gcc-4.1.2 output at -O2 for x86-64.
bar:
...
call foo
The more efficient version would be to generate 'jmp foo'
--
Summary: noreturn calls: gcc generates call instead of jump
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: vyzo at media dot mit dot edu
GCC target triplet: x86_64-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34589
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