Fix bug where comparing 32-bit values in static arrays or structs against 0 may give wrong results with large memory model.

The issue was that 16-bit absolute addressing (in the data bank) was being used to access the data to compare, but with the large memory model the static arrays or structs are not necessarily in the same bank, so absolute long addressing should be used.

This was sometimes causing failures in the C4.6.4.1.CC and C4.6.6.1.CC conformance tests in the ORCA/C test suite.

The following program often demonstrates the problem (depending on memory layout and contents):

#pragma memorymodel 1
#pragma optimize 1

#include <stdio.h>

int i;
char ch1[32000];
long L1[1];

int main (void)
{
    if (L1 [0] != 0)
        printf("%li\n", L1[0]); /* shouldn't print */

    /* buggy behavior can happen if the bank bytes of these pointers differ */
    printf("%p %p\n", &L1[0], &i);
}
This commit is contained in:
Stephen Heumann 2016-11-23 00:56:20 -06:00
parent fd48d77c60
commit 709f9b3f25
3 changed files with 12 additions and 5 deletions

View File

@ -119,6 +119,7 @@ const
m_ora_dir = 5; m_ora_dir = 5;
m_ora_dirX = 21; m_ora_dirX = 21;
m_ora_imm = 9; m_ora_imm = 9;
m_ora_long = 15;
m_ora_longX = 31; m_ora_longX = 31;
m_ora_s = 3; m_ora_s = 3;
m_pea = 244; m_pea = 244;

12
Gen.pas
View File

@ -1375,15 +1375,21 @@ var
begin {DoOr} begin {DoOr}
with op^ do begin with op^ do begin
if opcode = pc_ldo then begin if opcode = pc_ldo then begin
GenNative(m_lda_abs, absolute, q, lab, 0); if smallMemoryModel then begin
GenNative(m_ora_abs, absolute, q+2, lab, 0); GenNative(m_lda_abs, absolute, q, lab, 0);
GenNative(m_ora_abs, absolute, q+2, lab, 0);
end {if}
else begin
GenNative(m_lda_long, longabsolute, q, lab, 0);
GenNative(m_ora_long, longabsolute, q+2, lab, 0);
end; {else}
end {if} end {if}
else begin else begin
disp := LabelToDisp(r) + q; disp := LabelToDisp(r) + q;
if disp < 254 then begin if disp < 254 then begin
GenNative(m_lda_dir, direct, disp, nil, 0); GenNative(m_lda_dir, direct, disp, nil, 0);
GenNative(m_ora_dir, direct, disp+2, nil, 0); GenNative(m_ora_dir, direct, disp+2, nil, 0);
end {else if} end {if}
else begin else begin
GenNative(m_ldx_imm, immediate, disp, nil, 0); GenNative(m_ldx_imm, immediate, disp, nil, 0);
GenNative(m_lda_dirX, direct, 0, nil, 0); GenNative(m_lda_dirX, direct, 0, nil, 0);

View File

@ -765,8 +765,8 @@ case p_opcode of
m_adc_abs,m_adc_dir,m_adc_imm,m_adc_s,m_and_abs,m_and_dir,m_and_imm, m_adc_abs,m_adc_dir,m_adc_imm,m_adc_s,m_and_abs,m_and_dir,m_and_imm,
m_and_s,m_asl_a,m_dea,m_eor_abs,m_eor_dir,m_eor_imm,m_eor_s,m_lda_absx, m_and_s,m_asl_a,m_dea,m_eor_abs,m_eor_dir,m_eor_imm,m_eor_s,m_lda_absx,
m_lda_dirx,m_lda_indl,m_lda_indly,m_lda_longx,m_lda_s,m_lsr_a,m_ora_abs, m_lda_dirx,m_lda_indl,m_lda_indly,m_lda_longx,m_lda_s,m_lsr_a,m_ora_abs,
m_ora_dir,m_ora_dirX,m_ora_imm,m_ora_longX,m_ora_s,m_pla,m_sbc_abs, m_ora_dir,m_ora_dirX,m_ora_imm,m_ora_long,m_ora_longX,m_ora_s,m_pla,
m_sbc_dir,m_sbc_imm,m_sbc_s,m_tdc,m_tsc,m_tsb_dir,m_tsb_abs: m_sbc_abs,m_sbc_dir,m_sbc_imm,m_sbc_s,m_tdc,m_tsc,m_tsb_dir,m_tsb_abs:
aRegister.condition := regUnknown; aRegister.condition := regUnknown;
m_ldy_absX,m_ldy_dirX,m_ply: m_ldy_absX,m_ldy_dirX,m_ply: