https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108704
Bug ID: 108704
Summary: Many -Wanalyzer-use-of-uninitialized-value false
positives seen in qemu's softfloat.c
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: dmalcolm at gcc dot gnu.org
Target Milestone: ---
Created attachment 54425
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54425&action=edit
Reduced reproducer
Trunk shows many (dozens?) of -Wanalyzer-use-of-uninitialized-value false
positives on qemu's softfloat.c
https://godbolt.org/z/MTe9597Eh shows:
<source>: In function 'test':
<source>:27:9: warning: use of uninitialized value 'fp0' [CWE-457]
[-Wanalyzer-use-of-uninitialized-value]
27 | fp0 = floatx80_add(fp0, float32_to_floatx80((0x3F800000)));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'test': events 1-3
|
| 24 | floatx80 fp0;
| | ^~~
| | |
| | (1) region created on stack here
| | (2) capacity: 16 bytes
|......
| 27 | fp0 = floatx80_add(fp0, float32_to_floatx80((0x3F800000)));
| | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (3) use of uninitialized value 'fp0' here
|
Compiler returned: 0
where fp0 appears to have been initialized on the line above.
