diff options
Diffstat (limited to 'gcc/fwprop.c')
| -rw-r--r-- | gcc/fwprop.c | 130 |
1 files changed, 89 insertions, 41 deletions
diff --git a/gcc/fwprop.c b/gcc/fwprop.c index 45703fe..e6f3752 100644 --- a/gcc/fwprop.c +++ b/gcc/fwprop.c @@ -448,6 +448,18 @@ enum { PR_OPTIMIZE_FOR_SPEED = 4 }; +/* Check that X has a single def. */ + +static bool +reg_single_def_p (rtx x) +{ + if (!REG_P (x)) + return false; + + int regno = REGNO (x); + return (DF_REG_DEF_COUNT (regno) == 1 + && !bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)), regno)); +} /* Replace all occurrences of OLD in *PX with NEW and try to simplify the resulting expression. Replace *PX with a new RTL expression if an @@ -547,6 +559,54 @@ propagate_rtx_1 (rtx *px, rtx old_rtx, rtx new_rtx, int flags) tem = simplify_gen_subreg (mode, op0, GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); } + + else + { + rtvec vec; + rtvec newvec; + const char *fmt = GET_RTX_FORMAT (code); + rtx op; + + for (int i = 0; fmt[i]; i++) + switch (fmt[i]) + { + case 'E': + vec = XVEC (x, i); + newvec = vec; + for (int j = 0; j < GET_NUM_ELEM (vec); j++) + { + op = RTVEC_ELT (vec, j); + valid_ops &= propagate_rtx_1 (&op, old_rtx, new_rtx, flags); + if (op != RTVEC_ELT (vec, j)) + { + if (newvec == vec) + { + newvec = shallow_copy_rtvec (vec); + if (!tem) + tem = shallow_copy_rtx (x); + XVEC (tem, i) = newvec; + } + RTVEC_ELT (newvec, j) = op; + } + } + break; + + case 'e': + if (XEXP (x, i)) + { + op = XEXP (x, i); + valid_ops &= propagate_rtx_1 (&op, old_rtx, new_rtx, flags); + if (op != XEXP (x, i)) + { + if (!tem) + tem = shallow_copy_rtx (x); + XEXP (tem, i) = op; + } + } + break; + } + } + break; case RTX_OBJ: @@ -1370,10 +1430,11 @@ forward_propagate_and_simplify (df_ref use, rtx_insn *def_insn, rtx def_set) /* Given a use USE of an insn, if it has a single reaching definition, try to forward propagate it into that insn. - Return true if cfg cleanup will be needed. */ + Return true if cfg cleanup will be needed. + REG_PROP_ONLY is true if we should only propagate register copies. */ static bool -forward_propagate_into (df_ref use) +forward_propagate_into (df_ref use, bool reg_prop_only = false) { df_ref def; rtx_insn *def_insn, *use_insn; @@ -1394,10 +1455,6 @@ forward_propagate_into (df_ref use) if (DF_REF_IS_ARTIFICIAL (def)) return false; - /* Do not propagate loop invariant definitions inside the loop. */ - if (DF_REF_BB (def)->loop_father != DF_REF_BB (use)->loop_father) - return false; - /* Check if the use is still present in the insn! */ use_insn = DF_REF_INSN (use); if (DF_REF_FLAGS (use) & DF_REF_IN_NOTE) @@ -1415,6 +1472,19 @@ forward_propagate_into (df_ref use) if (!def_set) return false; + if (reg_prop_only + && (!reg_single_def_p (SET_SRC (def_set)) + || !reg_single_def_p (SET_DEST (def_set)))) + return false; + + /* Allow propagations into a loop only for reg-to-reg copies, since + replacing one register by another shouldn't increase the cost. */ + + if (DF_REF_BB (def)->loop_father != DF_REF_BB (use)->loop_father + && (!reg_single_def_p (SET_SRC (def_set)) + || !reg_single_def_p (SET_DEST (def_set)))) + return false; + /* Only try one kind of propagation. If two are possible, we'll do it on the following iterations. */ if (forward_propagate_and_simplify (use, def_insn, def_set) @@ -1483,7 +1553,7 @@ gate_fwprop (void) } static unsigned int -fwprop (void) +fwprop (bool fwprop_addr_p) { unsigned i; @@ -1502,11 +1572,16 @@ fwprop (void) df_ref use = DF_USES_GET (i); if (use) - if (DF_REF_TYPE (use) == DF_REF_REG_USE - || DF_REF_BB (use)->loop_father == NULL - /* The outer most loop is not really a loop. */ - || loop_outer (DF_REF_BB (use)->loop_father) == NULL) - forward_propagate_into (use); + { + if (DF_REF_TYPE (use) == DF_REF_REG_USE + || DF_REF_BB (use)->loop_father == NULL + /* The outer most loop is not really a loop. */ + || loop_outer (DF_REF_BB (use)->loop_father) == NULL) + forward_propagate_into (use, fwprop_addr_p); + + else if (fwprop_addr_p) + forward_propagate_into (use, false); + } } fwprop_done (); @@ -1537,7 +1612,7 @@ public: /* opt_pass methods: */ virtual bool gate (function *) { return gate_fwprop (); } - virtual unsigned int execute (function *) { return fwprop (); } + virtual unsigned int execute (function *) { return fwprop (false); } }; // class pass_rtl_fwprop @@ -1549,33 +1624,6 @@ make_pass_rtl_fwprop (gcc::context *ctxt) return new pass_rtl_fwprop (ctxt); } -static unsigned int -fwprop_addr (void) -{ - unsigned i; - - fwprop_init (); - - /* Go through all the uses. df_uses_create will create new ones at the - end, and we'll go through them as well. */ - for (i = 0; i < DF_USES_TABLE_SIZE (); i++) - { - if (!propagations_left) - break; - - df_ref use = DF_USES_GET (i); - if (use) - if (DF_REF_TYPE (use) != DF_REF_REG_USE - && DF_REF_BB (use)->loop_father != NULL - /* The outer most loop is not really a loop. */ - && loop_outer (DF_REF_BB (use)->loop_father) != NULL) - forward_propagate_into (use); - } - - fwprop_done (); - return 0; -} - namespace { const pass_data pass_data_rtl_fwprop_addr = @@ -1600,7 +1648,7 @@ public: /* opt_pass methods: */ virtual bool gate (function *) { return gate_fwprop (); } - virtual unsigned int execute (function *) { return fwprop_addr (); } + virtual unsigned int execute (function *) { return fwprop (true); } }; // class pass_rtl_fwprop_addr |