https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90340
Bug ID: 90340
Summary: Not optimal code when compiling C library for
vsnprintf, code size increase 17%
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: fredrik.hederstie...@securitas-direct.com
Target Milestone: ---
Created attachment 46284
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46284&action=edit
Testcase with example code <vsprintf.c> from Linux C library
When compiling some old Linux kernel library code for vsnprintf, the code
generated seems not optimal, and code size increased almost 17% for Cortex.M.
This was starting with gcc-9.1.0, previous versions did not show this.
(Generally when testing against CSiBE the overall average code size increased
with gcc-9.1.0 compared to previous version for the first time since gcc-4.6.0)
http://gcc.hederstierna.com/csibe/
Attached stripped example file from Linux library.
Compliled with -Os (makefile attached)
Gcc-8.2.0 generated more compact code size 806 bytes,
Gcc-9.1.0 generated some large switch table code size 942 bytes.
Difference is +136 bytes (+16.9%).
