From 628168c50264147e1b8b200833f25a4e166f5cd8 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Thu, 12 Sep 2002 04:33:58 +0000
Subject: [PATCH] Fix Borland C++ optimization bug; add test for bad DOS
 binaries.

---
 Mkfiles/Makefile.bc3 |  5 +++--
 test/testdos.asm     | 12 ++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 test/testdos.asm

diff --git a/Mkfiles/Makefile.bc3 b/Mkfiles/Makefile.bc3
index 80049ac2..d0453d1f 100644
--- a/Mkfiles/Makefile.bc3
+++ b/Mkfiles/Makefile.bc3
@@ -27,13 +27,14 @@
 
 CC = bcc                #compiler
 # opimizations
-OPTFLAGS = -d -O1 -Ogmpv -k-
+OPTFLAGS = -d -O1 -Ogmp -k-
   # -d  = merge duplicate strings
   # -O1 = optimize for size
   # -Og = enable global common subexpression elimination
   # -Om = enable loop invariant removal
   # -Op = enable constant propagation
-  # -Ov = enable strength-reduction optimization
+  # ** WARNING: DO NOT ENABLE -Ov (strength reduction) ON BORLAND C++ 3.1 **
+  # ** NASM IS KNOWN TO MISCOMPILE WITH -Ov **
   # -k- = omit stack frames where practical
 #output formats
 OUTFORMS = -DOF_ONLY -DOF_BIN -DOF_OBJ -DOF_WIN32 -DOF_AS86
diff --git a/test/testdos.asm b/test/testdos.asm
new file mode 100644
index 00000000..f03e52d0
--- /dev/null
+++ b/test/testdos.asm
@@ -0,0 +1,12 @@
+;
+; This file was known to miscompile with the 16-bit NASM built
+; under Borland C++ 3.1, so keep it around for testing...
+;
+; The proper output looks like:
+;
+; 00000000 A10300
+; 00000003 EA0000FFFF
+;
+	org 0100h
+	mov ax,[3]
+	jmp 0FFFFh:0000