From 7605b7bbf2cabbaf2e53a110ee9bb3eb5e6c4169 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Tue, 27 Mar 2018 20:11:45 -0500
Subject: [PATCH] Fix bug where bitwise binary ops on 32-bit values will be
 miscalculated and trash the stack in certain cases.

The following program (derived from a csmith-generated test case) demonstrates the crash:

#pragma optimize 8+64
#include <stdio.h>
long g = 0;
int main (void) {
    long l = 0x10305070;
    printf("%08lx\n", l ^ (g = (1 , 0x12345678)));
}
---
 Gen.pas | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Gen.pas b/Gen.pas
index 7f30571..e1487e8 100644
--- a/Gen.pas
+++ b/Gen.pas
@@ -3895,7 +3895,10 @@ procedure GenTree {op: icptr};
 	 lab1: integer;			{label number}
 
       begin {GenOp}
-      GenImplied(m_pla);
+      if gLong.where = A_X then
+         GenImplied(m_phx)
+      else
+         GenImplied(m_pla);
       if gLong.where = constant then begin
 	 GenNative(opi, immediate, long(gLong.lval).lsw, nil, 0);
 	 GenImplied(m_pha);