[Bug inline-asm/94113] Apparently incorrect register allocation in inline asm when using CMOV.

[contact at pgazz dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94113

--- Comment #4 from Paul  ---
That worked.  Thank you for the explanation!

[Bug inline-asm/94113] Apparently incorrect register allocation in inline asm when using CMOV.

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94113

Andrew Pinski  changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution|--- |INVALID

--- Comment #3 from Andrew Pinski  ---
You need an early clobber:
  __asm__ volatile("movl %3, %0;\n\t" \
   "cmpl $0, %1;\n\t" \
   "cmovne %2, %0;\n\t" \
   : "=&r"(final_result) \
   : "r"(cond), "r"(if_true), "r"(if_false) \
   : "cc" \
   );

Otherwise GCC thinks 0th operand and the second operand can be in the same
register.  With the early clobber it basically says the 0th operand cannot be
the same register as the other ones.

[Bug inline-asm/94113] Apparently incorrect register allocation in inline asm when using CMOV.

[contact at pgazz dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94113

--- Comment #2 from Paul  ---
Created attachment 48003
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48003&action=edit
The assembly output.

[Bug inline-asm/94113] Apparently incorrect register allocation in inline asm when using CMOV.

[contact at pgazz dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94113

--- Comment #1 from Paul  ---
Created attachment 48002
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48002&action=edit
The original C file.