From b00d4d3b5bbfc4c8e37e16833e54009cf528a852 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Mon, 30 Sep 2024 13:51:52 +0900
Subject: [PATCH] [qfcc] Respect parentheses when scattering sums

It may not be ideal at all times, but it does conform better with
general requirements for floating-point math.
---
 tools/qfcc/source/expr_algebra.c  | 12 ++++++------
 tools/qfcc/source/expr_dag.c      |  2 +-
 tools/qfcc/source/expr_optimize.c |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/tools/qfcc/source/expr_algebra.c b/tools/qfcc/source/expr_algebra.c
index d1098160c..012c0c59e 100644
--- a/tools/qfcc/source/expr_algebra.c
+++ b/tools/qfcc/source/expr_algebra.c
@@ -450,10 +450,10 @@ count_terms (const expr_t *expr)
 	auto e1 = expr->expr.e1;
 	auto e2 = expr->expr.e2;
 	int terms = !is_sum (e1) + !is_sum (e2);
-	if (is_sum (e1)) {
+	if (!e1->paren && is_sum (e1)) {
 		terms += count_terms (expr->expr.e1);
 	}
-	if (is_sum (e2)) {
+	if (!e2->paren && is_sum (e2)) {
 		terms += count_terms (expr->expr.e2);
 	}
 	return terms;
@@ -593,13 +593,13 @@ scatter_terms_core (const expr_t *sum,
 	bool subtract = (sum->expr.op == '-') ^ negative;
 	auto e1 = sum->expr.e1;
 	auto e2 = sum->expr.e2;
-	if (is_sum (e1)) {
+	if (!e1->paren && is_sum (e1)) {
 		scatter_terms_core (e1, adds, addind, subs, subind, negative);
 	}
-	if (is_sum (e2)) {
+	if (!e2->paren && is_sum (e2)) {
 		scatter_terms_core (e2, adds, addind, subs, subind, subtract);
 	}
-	if (!is_sum (e1)) {
+	if (e1->paren || !is_sum (e1)) {
 		auto e = sum->expr.e1;
 		auto arr = negative ^ is_neg (e) ? subs : adds;
 		auto ind = negative ^ is_neg (e) ? subind : addind;
@@ -608,7 +608,7 @@ scatter_terms_core (const expr_t *sum,
 		}
 		arr[(*ind)++] = e;
 	}
-	if (!is_sum (e2)) {
+	if (e2->paren || !is_sum (e2)) {
 		auto e = sum->expr.e2;
 		auto arr = subtract ^ is_neg (e) ? subs : adds;
 		auto ind = subtract ^ is_neg (e) ? subind : addind;
diff --git a/tools/qfcc/source/expr_dag.c b/tools/qfcc/source/expr_dag.c
index eb89f933c..52132ec88 100644
--- a/tools/qfcc/source/expr_dag.c
+++ b/tools/qfcc/source/expr_dag.c
@@ -58,7 +58,7 @@ edag_add_expr (const expr_t *expr)
 	}
 	for (size_t i = 0; i < expr_dag.size; i++) {
 		auto e = expr_dag.a[i];
-		if (e->type != expr->type) {
+		if (e->type != expr->type || e->paren != expr->paren) {
 			continue;
 		}
 		switch (expr->type) {
diff --git a/tools/qfcc/source/expr_optimize.c b/tools/qfcc/source/expr_optimize.c
index 707fcb54a..e5800346a 100644
--- a/tools/qfcc/source/expr_optimize.c
+++ b/tools/qfcc/source/expr_optimize.c
@@ -1,7 +1,7 @@
 /*
 	expr_optimize.c
 
-	 algebraic expression optimization
+	algebraic expression optimization
 
 	Copyright (C) 2023 Bill Currie <bill@taniwha.org>