https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108919
Bug ID: 108919
Summary: pure nested function may clobber its static chain
pointer in windowed ABI on xtensa
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: jcmvbkbc at gcc dot gnu.org
Target Milestone: ---
Created attachment 54525
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54525&action=edit
test.c
The following gfortran tests fail on windowed ABI xtensa target, but pass on
call0 ABI:
gfortran.dg/character_workout_1.f90 -O[123s] execution test
gfortran.dg/character_workout_4.f90 -O[123s] execution test
E.g. gfortran.dg/character_workout_1.f90 -O1 ends with the message 'STOP 209'.
This happens because in these tests pure nested functions are generated for
subroutines achar_cm and achar_am and the fwprop1 pass removes static chain
pointer initialization between the calls to these functions:
.L143:
addi a3, sp, 108
movi a4, 0xd4
add.n a4, sp, a4
addi a8, sp, -20
s32i.n a4, a8, 0
movi.n a11, 7
mov.n a10, a3
call8 achar_cm.21
movi.n a11, 7
mov.n a10, a3
call8 achar_am.15
Windowed ABI for xtensa specifies that the static chain is passed on the stack,
at offset -20 from the called function's CFA, i.e. outside the caller's stack
frame. This location may be overwritten if the called function makes function
calls that exceed certain depth.
The issue may be reproduced with the attached small test case.
