[Bug tree-optimization/125653] [17 regression] glibc printf miscompiled since r17-1238-g8e3eff39a4564c

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125653

--- Comment #3 from Sam James <sjames at gcc dot gnu.org> ---
Created attachment 64659
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64659&action=edit
vfprintf-internal.i.xz

stdio-common/vfprintf-internal.c's Xprintf_buffer is miscompiled. Attached
vfprintf-internal.i.

```
gcc vfprintf-internal.c -c -std=gnu11 -fgnu89-inline  -O2 -march=znver2 -Wall
-Wwrite-strings -Wundef -Wimplicit-fallthrough -fmerge-all-constants
-frounding-math -ftrapping-math -fno-stack-protector -fno-common
-U_FORTIFY_SOURCE -Wstrict-prototypes -Wold-style-definition -Wfree-labels
-Wmissing-parameter-name -fmath-errno    -fPIE     -ftls-model=initial-exec    
-I../include -I/tmp/g2/stdio-common  -I/tmp/g2 
-I../sysdeps/unix/sysv/linux/x86_64/64  -I../sysdeps/x86_64/64/nptl 
-I../sysdeps/unix/sysv/linux/x86_64/include -I../sysdeps/unix/sysv/linux/x86_64
 -I../sysdeps/unix/sysv/linux/x86/include -I../sysdeps/unix/sysv/linux/x86 
-I../sysdeps/x86/nptl  -I../sysdeps/unix/sysv/linux/wordsize-64 
-I../sysdeps/x86_64/nptl  -I../sysdeps/unix/sysv/linux/include
-I../sysdeps/unix/sysv/linux  -I../sysdeps/nptl  -I../sysdeps/pthread 
-I../sysdeps/gnu  -I../sysdeps/unix/inet  -I../sysdeps/unix/sysv 
-I../sysdeps/unix/x86_64  -I../sysdeps/unix  -I../sysdeps/posix 
-I../sysdeps/x86_64/64  -I../sysdeps/x86_64/fpu/multiarch 
-I../sysdeps/x86_64/fpu  -I../sysdeps/x86/fpu  -I../sysdeps/x86_64/multiarch 
-I../sysdeps/x86_64  -I../sysdeps/x86/include -I../sysdeps/x86 
-I../sysdeps/ieee754/float128  -I../sysdeps/ieee754/ldbl-96/include
-I../sysdeps/ieee754/ldbl-96  -I../sysdeps/ieee754/dbl-64 
-I../sysdeps/ieee754/flt-32  -I../sysdeps/wordsize-64  -I../sysdeps/ieee754 
-I../sysdeps/generic  -I.. -I../libio -I.  -D_LIBC_REENTRANT -include
/tmp/g2/libc-modules.h -DMODULE_NAME=libc -include ../include/libc-symbols.h 
-DPIC     -DTOP_NAMESPACE=glibc -D_IO_MTSAFE_IO -o
/tmp/g2/stdio-common/vfprintf-internal.o -MD -MP -MF
/tmp/g2/stdio-common/vfprintf-internal.o.dt -MT
/tmp/g2/stdio-common/vfprintf-internal.o -save-temps
```