[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Effective way to test PowerPC lwbrx instruction
From: |
G 3 |
Subject: |
[Qemu-devel] Effective way to test PowerPC lwbrx instruction |
Date: |
Thu, 25 Aug 2016 14:54:25 -0400 |
I'm chasing down a bug with QEMU that causes audio to fail on a Mac
OS guest. In this file: https://github.com/nixxcode/
AppleUSBAudio-273.4.1/blob/master/AppleUSBAudioClip.cpp is where a
lot of assembly language code is located. I think one or more of the
PowerPC instructions might be incorrectly implemented so I am
checking each one that the file uses. Starting with lwbrx I made this
program that gives this instruction sample inputs and checks them
with real outputs. According to the program QEMU implements this
instruction correctly. Does this program effectively check the lwbrx
instruction or is it missing something?
#include <stdio.h>
// instructions to test
// lwbrx, lhbrx, rlwimi, stwbrx, stfiwx, fctiw, fmadd, sthbrx, mffs,
// mtfsf
void test_lwbrx()
{
// http://www.ds.ewi.tudelft.nl/vakken/in1006/instruction-set/
lwbrx.html
// rA can be 0, 4, 8, 12
long index, result, rA;
const int rB_size = 32;
long rB[rB_size];
long *answer_array;
float total, correct;
// answers with rA = 0
long answer_array0[] = {0x0, 0x78563412, 0xf0ac6824, 0x68039d36,
0xe059d148,
0x58b0055b, 0xd0063a6d, 0x485d6e7f, 0xc0b3a291, 0x380ad7a3,
0xb0600bb6,
0x28b73fc8, 0xa00d74da, 0x1864a8ec, 0x90badcfe, 0x8111111,
0x80674523,
0xf8bd7935, 0x7014ae47, 0xe86ae259, 0x60c1166c, 0xd8174b7e,
0x506e7f90,
0xc8c4b3a2, 0x401be8b4, 0xb8711cc7, 0x30c850d9, 0xa81e85eb,
0x2075b9fd,
0x98cbed0f, 0x10222222, 0x88785634};
// answers with rA = 4
long answer_array4[] = {0x78563412, 0xf0ac6824, 0x68039d36,
0xe059d148,
0x58b0055b, 0xd0063a6d, 0x485d6e7f, 0xc0b3a291, 0x380ad7a3,
0xb0600bb6,
0x28b73fc8, 0xa00d74da, 0x1864a8ec, 0x90badcfe, 0x8111111,
0x80674523,
0xf8bd7935, 0x7014ae47, 0xe86ae259, 0x60c1166c, 0xd8174b7e,
0x506e7f90,
0xc8c4b3a2, 0x401be8b4, 0xb8711cc7, 0x30c850d9, 0xa81e85eb,
0x2075b9fd,
0x98cbed0f, 0x10222222, 0x88785634, 0x0};
// answers with rA = 8
long answer_array8[] = {0xf0ac6824, 0x68039d36, 0xe059d148,
0x58b0055b,
0xd0063a6d, 0x485d6e7f, 0xc0b3a291, 0x380ad7a3, 0xb0600bb6,
0x28b73fc8,
0xa00d74da, 0x1864a8ec, 0x90badcfe, 0x8111111, 0x80674523,
0xf8bd7935,
0x7014ae47, 0xe86ae259, 0x60c1166c, 0xd8174b7e, 0x506e7f90,
0xc8c4b3a2,
0x401be8b4, 0xb8711cc7, 0x30c850d9, 0xa81e85eb, 0x2075b9fd,
0x98cbed0f,
0x10222222, 0x88785634, 0x0, 0x0};
// answers with rA = 12
long answer_array12[] = {0x68039d36, 0xe059d148, 0x58b0055b,
0xd0063a6d,
0x485d6e7f, 0xc0b3a291, 0x380ad7a3, 0xb0600bb6, 0x28b73fc8,
0xa00d74da,
0x1864a8ec, 0x90badcfe, 0x8111111, 0x80674523, 0xf8bd7935,
0x7014ae47,
0xe86ae259, 0x60c1166c, 0xd8174b7e, 0x506e7f90, 0xc8c4b3a2,
0x401be8b4,
0xb8711cc7, 0x30c850d9, 0xa81e85eb, 0x2075b9fd, 0x98cbed0f,
0x10222222,
0x88785634, 0x0, 0x0, 0x0};
// Fill up rB array
for(index = 0; index < rB_size; index++)
{
rB[index] = 0x12345678 * index;
}
total = 0;
correct = 0;
// Go thru each rA value
for(rA = 0; rA <=12; rA=rA+4)
{
// set the correct answer array for each rA value
if(rA == 0)
answer_array = answer_array0;
else if(rA == 4)
answer_array = answer_array4;
else if(rA == 8)
answer_array = answer_array8;
else
answer_array = answer_array12;
// Go thru each rB value
for(index = 0; index < rB_size; index++)
{
asm volatile("lwbrx %0, %1, %2" : "=r" (result) : "b
%" (rA), "r" (&(rB[index])));
printf("lwbrx rA: %d rB: 0x%x result: 0x%x", rA, rB
[index], result);
//printf("0x%x, ", result); // used to make answers
total++;
// check recorded answer with calculated answer
if(result == answer_array[index]) {
printf(" correct\n");
correct++;
} else {
printf(" WRONG! should be 0x%x\n", answer_array
[index]);
}
}
}
printf("Percent correct: %.2f%c\n", correct/total*100, '%');
}
int main (int argc, const char * argv[]) {
test_lwbrx();
return 0;
}
This program was tested on a real PowerPC G3 and G5. The results were
100% when ran in QEMU in a Mac OS 10.4 guest.
- [Qemu-devel] Effective way to test PowerPC lwbrx instruction,
G 3 <=