Robert Suchanek <robert.sucha...@imgtec.com> writes: > Hi, > > It was discovered that with the attached test case compiled with -O2 > -funroll-loops, the regrename pass renamed one of the registers ($2) > to $8 that was not saved by the prologue. > > The attached patch fixes it by defining macro HARD_REGNO_RENAME_OK > that returns zero iff the current function is an interrupt handler and > a register was never live. > > Regression is still in progress. Ok to apply if it passes? > > Regards, > Robert > > gcc/ > * config/mips/mips-protos.h (mips_hard_regno_rename_ok): New prototype. > * config/mips/mips.c (mips_hard_regno_rename_ok): New function. > * config/mips/mips.h (HARD_REGNO_RENAME_OK): New. > > gcc/testsuite/ > * gcc.target/mips/interrupt_handler-bug-1.c: New test.
You also need to do the same thing for TARGET_HARD_REGNO_SCRATCH_OK, to stop peephole2 from using unsaved registers as scratch registers. I should dig out my patches to clean up this interface. It's just too brittle to have two macros that say what registers can be used after reload. Thanks, Richard
