From 83fb5887273fa9d9900ff966801a66c5ecdf7d53 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Mon, 10 Jun 2019 08:44:36 +0900
Subject: [PATCH] Support vector/quaternion division by float

Implemented via v*(1/f) or q*(1/f) to give CSE a chance to optimize the
division if necessary as otherwise the engine would have to divide every
time.
---
 tools/qfcc/source/expr_binary.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/qfcc/source/expr_binary.c b/tools/qfcc/source/expr_binary.c
index d53d3677c..2029726af 100644
--- a/tools/qfcc/source/expr_binary.c
+++ b/tools/qfcc/source/expr_binary.c
@@ -46,6 +46,7 @@ typedef struct {
 } expr_type_t;
 
 static expr_t *pointer_arithmetic (int op, expr_t *e1, expr_t *e2);
+static expr_t *inverse_multiply (int op, expr_t *e1, expr_t *e2);
 
 static expr_type_t string_string[] = {
 	{'+',	&type_string},
@@ -85,7 +86,7 @@ static expr_type_t float_vector[] = {
 
 static expr_type_t float_quat[] = {
 	{'*',	&type_quaternion},
-	{'/',	&type_quaternion},
+	{'/',	0, 0, 0, inverse_multiply},
 	{0, 0}
 };
 
@@ -113,7 +114,7 @@ static expr_type_t float_integer[] = {
 
 static expr_type_t vector_float[] = {
 	{'*',	&type_vector},
-	{'/',	&type_vector},
+	{'/',	0, 0, 0, inverse_multiply},
 	{0, 0}
 };
 
@@ -601,6 +602,15 @@ pointer_arithmetic (int op, expr_t *e1, expr_t *e2)
 	return cast_expr (ptype, e);
 }
 
+static expr_t *
+inverse_multiply (int op, expr_t *e1, expr_t *e2)
+{
+	// There is no vector/float or quaternion/float instruction and adding
+	// one would mean the engine would have to do 1/f every time
+	expr_t     *one = new_float_expr (1);
+	return binary_expr ('*', e1, binary_expr ('/', one, e2));
+}
+
 static expr_t *
 invalid_binary_expr (int op, expr_t *e1, expr_t *e2)
 {