diff options
Diffstat (limited to 'gcc/df-problems.c')
| -rw-r--r-- | gcc/df-problems.c | 110 |
1 files changed, 97 insertions, 13 deletions
diff --git a/gcc/df-problems.c b/gcc/df-problems.c index 25dea30..829698b 100644 --- a/gcc/df-problems.c +++ b/gcc/df-problems.c @@ -3759,24 +3759,19 @@ df_simulate_fixup_sets (basic_block bb, bitmap live) The following three functions are used only for BACKWARDS scanning: i.e. they process the defs before the uses. - df_simulate_artificial_refs_at_end should be called first with a + df_simulate_initialize_backwards should be called first with a bitvector copyied from the DF_LIVE_OUT or DF_LR_OUT. Then - df_simulate_one_insn should be called for each insn in the block, - starting with the last on. Finally, - df_simulate_artificial_refs_at_top can be called to get a new value + df_simulate_one_insn_backwards should be called for each insn in + the block, starting with the last on. Finally, + df_simulate_finalize_backwards can be called to get a new value of the sets at the top of the block (this is rarely used). - - It would be not be difficult to define a similar set of functions - that work in the forwards direction. In that case the functions - would ignore the use sets and look for the REG_DEAD and REG_UNUSED - notes. -----------------------------------------------------------------------------*/ + ----------------------------------------------------------------------------*/ /* Apply the artificial uses and defs at the end of BB in a backwards direction. */ void -df_simulate_artificial_refs_at_end (basic_block bb, bitmap live) +df_simulate_initialize_backwards (basic_block bb, bitmap live) { df_ref *def_rec; df_ref *use_rec; @@ -3801,7 +3796,7 @@ df_simulate_artificial_refs_at_end (basic_block bb, bitmap live) /* Simulate the backwards effects of INSN on the bitmap LIVE. */ void -df_simulate_one_insn (basic_block bb, rtx insn, bitmap live) +df_simulate_one_insn_backwards (basic_block bb, rtx insn, bitmap live) { if (! INSN_P (insn)) return; @@ -3816,7 +3811,7 @@ df_simulate_one_insn (basic_block bb, rtx insn, bitmap live) direction. */ void -df_simulate_artificial_refs_at_top (basic_block bb, bitmap live) +df_simulate_finalize_backwards (basic_block bb, bitmap live) { df_ref *def_rec; #ifdef EH_USES @@ -3840,3 +3835,92 @@ df_simulate_artificial_refs_at_top (basic_block bb, bitmap live) } #endif } +/*---------------------------------------------------------------------------- + The following three functions are used only for FORWARDS scanning: + i.e. they process the defs and the REG_DEAD and REG_UNUSED notes. + Thus it is important to add the DF_NOTES problem to the stack of + problems computed before using these functions. + + df_simulate_initialize_forwards should be called first with a + bitvector copyied from the DF_LIVE_IN or DF_LR_IN. Then + df_simulate_one_insn_forwards should be called for each insn in + the block, starting with the last on. Finally, + df_simulate_finalize_forwards can be called to get a new value + of the sets at the bottom of the block (this is rarely used). + ----------------------------------------------------------------------------*/ + +/* Apply the artificial uses and defs at the top of BB in a backwards + direction. */ + +void +df_simulate_initialize_forwards (basic_block bb, bitmap live) +{ + df_ref *def_rec; + int bb_index = bb->index; + + for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++) + { + df_ref def = *def_rec; + if (DF_REF_FLAGS (def) & DF_REF_AT_TOP) + bitmap_clear_bit (live, DF_REF_REGNO (def)); + } +} + +/* Simulate the backwards effects of INSN on the bitmap LIVE. */ + +void +df_simulate_one_insn_forwards (basic_block bb, rtx insn, bitmap live) +{ + rtx link; + if (! INSN_P (insn)) + return; + + /* Make sure that the DF_NOTES really is an active df problem. */ + gcc_assert (df_note); + + df_simulate_defs (insn, live); + + /* Clear all of the registers that go dead. */ + for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) + { + switch (REG_NOTE_KIND (link)) + case REG_DEAD: + case REG_UNUSED: + { + rtx reg = XEXP (link, 0); + int regno = REGNO (reg); + if (regno < FIRST_PSEUDO_REGISTER) + { + int n = hard_regno_nregs[regno][GET_MODE (reg)]; + while (--n >= 0) + bitmap_clear_bit (live, regno + n); + } + else + bitmap_clear_bit (live, regno); + break; + default: + break; + } + } + df_simulate_fixup_sets (bb, live); +} + + +/* Apply the artificial uses and defs at the end of BB in a backwards + direction. */ + +void +df_simulate_finalize_forwards (basic_block bb, bitmap live) +{ + df_ref *def_rec; + int bb_index = bb->index; + + for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++) + { + df_ref def = *def_rec; + if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0) + bitmap_clear_bit (live, DF_REF_REGNO (def)); + } +} + + |