From cb99b3778eb77e98ec1465711107147c8422bb48 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Sun, 31 Jan 2021 08:52:50 -0600
Subject: [PATCH] Flag that conversions may not set CPU flags usable for a
 subsequent comparison.

There are several conversions that do not set the necessary flags, so they must be set separately before doing a comparison. Without this fix, comparisons of a value that was just converted might be mis-evaluated.

This led to bugs where the wrong side of an "if" could be followed in some cases, as in the below examples:

#include <stdio.h>
int g(void) {return 50;}
signed char h(void) {return 50;}
long lf(void) {return 50;}
int main(void) {
    signed char sc = 50;
    if ((int)(signed char)g()) puts("OK1");
    if ((int)h()) puts("OK2");
    if ((int)sc) puts("OK3");
    if ((int)lf()) puts("OK4");
}
---
 Gen.pas | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Gen.pas b/Gen.pas
index 4d808ef..78a9457 100644
--- a/Gen.pas
+++ b/Gen.pas
@@ -405,7 +405,7 @@ NeedsCondition := opcode in
    [pc_and,pc_ior,pc_cui,pc_cup,pc_lor,pc_lnd,pc_ldl,pc_lil,pc_lld,
     pc_lli,pc_gil,pc_gli,pc_gdl,pc_gld,pc_iil,pc_ili,pc_idl,pc_ild,
     pc_cop,pc_cpo,pc_cpi,pc_dvi,pc_mpi,pc_adi,pc_sbi,pc_mod,pc_bno,
-    pc_udi,pc_uim,pc_umi];
+    pc_udi,pc_uim,pc_umi,pc_cnv];
 end; {NeedsCondition}