diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/ifcvt.c | 12 |
2 files changed, 12 insertions, 5 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a91944e..3acd226 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2006-08-27 Roger Sayle <roger@eyesopen.com> + + * ifcvt.c (cheap_bb_rtx_cost_p): Don't speculatively execute + x87 instructions. + 2006-08-27 Kazu Hirata <kazu@codesourcery.com> * config/i386/crtfastmath.c: Fix a comment typo. diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 4787a24..987a2fb 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -1,5 +1,5 @@ /* If-conversion support. - Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 + Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. This file is part of GCC. @@ -153,14 +153,16 @@ cheap_bb_rtx_cost_p (basic_block bb, int max_cost) /* If this instruction is the load or set of a "stack" register, such as a floating point register on x87, then the cost of - speculatively executing this instruction needs to include - the additional cost of popping this register off of the - register stack. */ + speculatively executing this insn may need to include + the additional cost of popping its result off of the + register stack. Unfortunately, correctly recognizing and + accounting for this additional overhead is tricky, so for + now we simply prohibit such speculative execution. */ #ifdef STACK_REGS { rtx set = single_set (insn); if (set && STACK_REG_P (SET_DEST (set))) - cost += COSTS_N_INSNS (1); + return false; } #endif |