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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-08-21 12:18:00 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-08-21 22:16:01 +0200 |
| commit | 31996b8c7ff1dad6da5c56e16de7097f3a87c474 (patch) | |
| tree | 2db09192c4a06f6c3e11e1ce08923a2766a73eff | |
| parent | 136cc7ed387be8e0309d4f7b7b99ed5a4851907a (diff) | |
| download | sparse-dev-31996b8c7ff1dad6da5c56e16de7097f3a87c474.tar.gz | |
doc: convert existing simplify.c doc into ReST autodoc
Some functions in simplify.c are already documented.
Convert this documentation to sparse's Sphinx based doc system.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 79 |
1 files changed, 43 insertions, 36 deletions
@@ -4,6 +4,10 @@ * Copyright (C) 2004 Linus Torvalds */ +/// +// Instruction simplification +// -------------------------- + #include <assert.h> #include "parse.h" @@ -12,7 +16,12 @@ #include "flow.h" #include "symbol.h" -/* Find the trivial parent for a phi-source */ +/// +// Utilities +// ^^^^^^^^^ + +/// +// find the trivial parent for a phi-source static struct basic_block *phi_parent(struct basic_block *source, pseudo_t pseudo) { /* Can't go upwards if the pseudo is defined in the bb it came from.. */ @@ -26,16 +35,15 @@ static struct basic_block *phi_parent(struct basic_block *source, pseudo_t pseud return first_basic_block(source->parents); } -/* - * Copy the phi-node's phisrcs into to given array. - * Returns 0 if the the list contained the expected - * number of element, a positive number if there was - * more than expected and a negative one if less. - * - * Note: we can't reuse a function like linearize_ptr_list() - * because any VOIDs in the phi-list must be ignored here - * as in this context they mean 'entry has been removed'. - */ +/// +// copy the phi-node's phisrcs into to given array +// @return: 0 if the the list contained the expected +// number of element, a positive number if there was +// more than expected and a negative one if less. +// +// :note: we can't reuse a function like linearize_ptr_list() +// because any VOIDs in the phi-list must be ignored here +// as in this context they mean 'entry has been removed'. static int get_phisources(struct instruction *sources[], int nbr, struct instruction *insn) { pseudo_t phi; @@ -227,15 +235,16 @@ static void kill_use_list(struct pseudo_list *list) } END_FOR_EACH_PTR(p); } -/* - * kill an instruction: - * - remove it from its bb - * - remove the usage of all its operands - * If forse is zero, the normal case, the function only for - * instructions free of (possible) side-effects. Otherwise - * the function does that unconditionally (must only be used - * for unreachable instructions. - */ +/// +// kill an instruction +// @insn: the instruction to be killed +// @force: if unset, the normal case, the instruction is not killed +// if not free of possible side-effect; if set the instruction +// is unconditionally killed. +// +// The killed instruction is removed from its BB and the usage +// of all its operands are removed. The instruction is also +// marked as killed by setting its ->bb to NULL. int kill_insn(struct instruction *insn, int force) { if (!insn || !insn->bb) @@ -315,9 +324,8 @@ int kill_insn(struct instruction *insn, int force) return repeat_phase |= REPEAT_CSE; } -/* - * Kill trivially dead instructions - */ +/// +// kill trivially dead instructions static int dead_insn(struct instruction *insn, pseudo_t *src1, pseudo_t *src2, pseudo_t *src3) { if (has_users(insn->target)) @@ -399,12 +407,11 @@ static unsigned int value_size(long long value) return 64; } -/* - * Try to determine the maximum size of bits in a pseudo. - * - * Right now this only follow casts and constant values, but we - * could look at things like logical 'and' instructions etc. - */ +/// +// try to determine the maximum size of bits in a pseudo +// +// Right now this only follow casts and constant values, but we +// could look at things like AND instructions, etc. static unsigned int operand_size(struct instruction *insn, pseudo_t pseudo) { unsigned int size = insn->size; @@ -1196,10 +1203,11 @@ offset: return REPEAT_CSE | REPEAT_SYMBOL_CLEANUP; } -/* - * We walk the whole chain of adds/subs backwards. That's not - * only more efficient, but it allows us to find loops. - */ +/// +// simplify memops instructions +// +// :note: We walk the whole chain of adds/subs backwards. +// That's not only more efficient, but it allows us to find loops. static int simplify_memop(struct instruction *insn) { int one, ret = 0; @@ -1417,9 +1425,8 @@ static int simplify_range(struct instruction *insn) return 0; } -/* - * Simplify "set_ne/eq $0 + br" - */ +/// +// simplify SET_NE/EQ $0 + BR static int simplify_cond_branch(struct instruction *br, struct instruction *def, pseudo_t newcond) { replace_pseudo(br, &br->cond, newcond); |