From fa4147a284e4d7b50175e0252bbd4ecf431cb7fd Mon Sep 17 00:00:00 2001
From: "Jan (janneke) Nieuwenhuizen" <janneke@gnu.org>
Date: Tue, 6 Oct 2020 19:41:14 +0200
Subject: [PATCH] mescc: Use signed division for x86, x86_64 when appropriate.

This fixes 36-compare-arithmetic.c

* module/mescc/i386/as.scm (i386:r0/r1, i386:r0%r1): Do not reset
signed?.
* module/mescc/x86_64/as.scm (x86_64:r0/r1, x86_64:r0%r1): Likewise.
* lib/tests/scaffold/36-compare-arithmetic.c (main): Use unique exit
value per failure.
---
 lib/tests/scaffold/36-compare-arithmetic.c | 16 ++++++++--------
 module/mescc/i386/as.scm                   |  6 ++----
 module/mescc/x86_64/as.scm                 |  6 ++----
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/lib/tests/scaffold/36-compare-arithmetic.c b/lib/tests/scaffold/36-compare-arithmetic.c
index a138aef9..a8ed0573 100644
--- a/lib/tests/scaffold/36-compare-arithmetic.c
+++ b/lib/tests/scaffold/36-compare-arithmetic.c
@@ -1,6 +1,6 @@
 /* -*-comment-start: "//";comment-end:""-*-
  * GNU Mes --- Maxwell Equations of Software
- * Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ * Copyright © 2017,2018,2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
  *
  * This file is part of GNU Mes.
  *
@@ -30,31 +30,31 @@ main ()
 
   oputs ("t: 2 - 1\n");
   if (0)
-    return 1;
+    return 2;
 
   oputs ("t: 1 << 3\n");
   if (1 << 3 != 8)
-    return 1;
+    return 3;
 
   oputs ("t: 8 >> 3\n");
   if (8 >> 3 != 1)
-    return 1;
+    return 4;
 
   oputs ("t: 8 / 4\n");
   if (8 / 4 != 2)
-    return 1;
+    return 5;
 
   oputs ("t: 8 / -4\n");
   if (8 / -4 != -2)
-    return 1;
+    return 6;
 
   oputs ("t: -8 / -4\n");
   if (-8 / -4 != 2)
-    return 1;
+    return 7;
 
   oputs ("t: -8 / 4\n");
   if (-8 / 4 != -2)
-    return 1;
+    return 8;
 
   return 0;
 }
diff --git a/module/mescc/i386/as.scm b/module/mescc/i386/as.scm
index 387e3b7a..0b786e5b 100644
--- a/module/mescc/i386/as.scm
+++ b/module/mescc/i386/as.scm
@@ -355,8 +355,7 @@
     `((,(string-append "and____%" r1 ",%" r0)))))
 
 (define (i386:r0/r1 info signed?)
-  (let ((signed? #f)              ; nobody knows, -- all advice are belong to us?
-        (allocated (.allocated info))
+  (let ((allocated (.allocated info))
         (r0 (get-r0 info))
         (r1 (get-r1 info)))
     (if (not (member "edx" allocated))
@@ -381,8 +380,7 @@
           ("pop____%eax")))))
 
 (define (i386:r0%r1 info signed?)
-  (let ((signed? #f)              ; nobody knows, -- all advice are belong to us?
-        (allocated (.allocated info))
+  (let ((allocated (.allocated info))
         (r0 (get-r0 info))
         (r1 (get-r1 info)))
     (if (not (member "edx" allocated))
diff --git a/module/mescc/x86_64/as.scm b/module/mescc/x86_64/as.scm
index fe98452d..7e438c6c 100644
--- a/module/mescc/x86_64/as.scm
+++ b/module/mescc/x86_64/as.scm
@@ -435,8 +435,7 @@
     `((,(string-append "and____%" r1 ",%" r0)))))
 
 (define (x86_64:r0/r1 info signed?)
-  (let ((signed? #f)              ; nobody knows, -- all advice are belong to us?
-        (allocated (.allocated info))
+  (let ((allocated (.allocated info))
         (r0 (get-r0 info))
         (r1 (get-r1 info)))
     (if (not (member "rdx" allocated))
@@ -461,8 +460,7 @@
           ("pop____%rax")))))
 
 (define (x86_64:r0%r1 info signed?)
-  (let ((signed? #f)              ; nobody knows, -- all advice are belong to us?
-        (allocated (.allocated info))
+  (let ((allocated (.allocated info))
         (r0 (get-r0 info))
         (r1 (get-r1 info)))
     (if (not (member "rdx" allocated))