diff options
Diffstat (limited to 'gcc/emit-rtl.c')
| -rw-r--r-- | gcc/emit-rtl.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c index 2c70fb1..59cd38d 100644 --- a/gcc/emit-rtl.c +++ b/gcc/emit-rtl.c @@ -2580,10 +2580,14 @@ verify_rtx_sharing (rtx orig, rtx insn) case RETURN: case SIMPLE_RETURN: case SCRATCH: - return; /* SCRATCH must be shared because they represent distinct values. */ + return; case CLOBBER: - if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) + /* Share clobbers of hard registers (like cc0), but do not share pseudo reg + clobbers or clobbers of hard registers that originated as pseudos. + This is needed to allow safe register renaming. */ + if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER + && ORIGINAL_REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 0))) return; break; @@ -2797,7 +2801,11 @@ repeat: /* SCRATCH must be shared because they represent distinct values. */ return; case CLOBBER: - if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) + /* Share clobbers of hard registers (like cc0), but do not share pseudo reg + clobbers or clobbers of hard registers that originated as pseudos. + This is needed to allow safe register renaming. */ + if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER + && ORIGINAL_REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 0))) return; break; @@ -5303,7 +5311,11 @@ copy_insn_1 (rtx orig) case SIMPLE_RETURN: return orig; case CLOBBER: - if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER) + /* Share clobbers of hard registers (like cc0), but do not share pseudo reg + clobbers or clobbers of hard registers that originated as pseudos. + This is needed to allow safe register renaming. */ + if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER + && ORIGINAL_REGNO (XEXP (orig, 0)) == REGNO (XEXP (orig, 0))) return orig; break; |