https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66265
Bug ID: 66265
Summary: strict aliasing with O2 fails to generate correct code
and gives no warnings
Product: gcc
Version: 4.8.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: gougolith at gmail dot com
Target Milestone: ---
Created attachment 35607
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35607&action=edit
Sample code that exhibits the issue.
This may be a genuine bug since the issue manifests itself depending on the way
the memory allocation is done. Clearly the pointers are all the same type.
I turned on the following flags to generate the code:
gcc -Wall -O2 -pedantic -Wextra -Wall
Generates no warnings of any kind but the program is broken.
gcc -Wall -O2 -pedantic -Wextra -Wall -fno-strict-aliasing
Generates no warnings and correct program.
I'm sure this is a strict-aliasing issue but it makes no sense why no warning
is issued if that's the case?
