From 87a43777ab37a0c1c4c82997fdfb27c6a4ffa834 Mon Sep 17 00:00:00 2001 From: Dale Weiler Date: Sat, 23 Nov 2013 13:13:21 -0500 Subject: [PATCH] strength reduct (a - (-b)) into (a + b) --- ast.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/ast.c b/ast.c index 3c70a73..7b2da4d 100644 --- a/ast.c +++ b/ast.c @@ -441,6 +441,21 @@ ast_binary* ast_binary_new(lex_ctx_t ctx, int op, ast_instantiate(ast_binary, ctx, ast_binary_delete); ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_binary_codegen); + if (ast_istype(right, ast_unary) && OPTS_OPTIMIZATION(OPTIM_PEEPHOLE)) { + ast_expression *normal = ((ast_unary*)right)->operand; + + /* make a-(-b) => a + b */ + if (op == INSTR_SUB_F) { + op = INSTR_ADD_F; + right = normal; + ++opts_optimizationcount[OPTIM_PEEPHOLE]; + } else if (op == INSTR_SUB_V) { + op = INSTR_ADD_V; + right = normal; + ++opts_optimizationcount[OPTIM_PEEPHOLE]; + } + } + self->op = op; self->left = left; self->right = right; -- 2.39.2