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<head>
<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - wrong code with "opt -gvn -instcombine -jump-threading -structurizecfg -reg2mem -mem2reg -structurizecfg -called-value-propagation""
href="https://bugs.llvm.org/show_bug.cgi?id=41699">41699</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>wrong code with "opt -gvn -instcombine -jump-threading -structurizecfg -reg2mem -mem2reg -structurizecfg -called-value-propagation"
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>8.0
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>cszide@163.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=21866" name="attach_21866" title=".bc file of the source code">attachment 21866</a> <a href="attachment.cgi?id=21866&action=edit" title=".bc file of the source code">[details]</a></span>
.bc file of the source code
$clang -v
clang version 8.0.0 (tags/RELEASE_800/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir:
/home/jack-zhou/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$clang -O3 -c -emit-llvm -mllvm -disable-llvm-optzns small.c -o small.bc
$clang small.bc -o small1.out && ./small1.out
checksum = 9ADD2096
$ /home/jack-zhou/clang+llvm-8.0.0-x86_64-linux-gnu-ubuntu-18.04/bin/opt -gvn
-instcombine -jump-threading -structurizecfg -reg2mem -mem2reg -structurizecfg
-called-value-propagation small.bc -o small-opt.bc
$clang small-opt.bc -o small2.out && ./small2.out
checksum = 56772008
--------------------------------------------------------------
#include <stdio.h>
typedef signed char int8_t;
typedef short int int16_t;
typedef int int32_t;
typedef long int int64_t;
typedef unsigned char uint8_t;
typedef unsigned short int uint16_t;
typedef unsigned int uint32_t;
typedef unsigned long int uint64_t;
static uint32_t crc32_tab[256];
static uint32_t crc32_context = 0xFFFFFFFFUL;
static void crc32_gentab(void) {
uint32_t crc;
const uint32_t poly = 0xEDB88320UL;
int i, j;
for (i = 0; i < 256; i++) {
crc = i;
for (j = 8; j > 0; j--) {
if (crc & 1) {
crc = (crc >> 1) ^ poly;
} else {
crc >>= 1;
}
}
crc32_tab[i] = crc;
}
}
static void crc32_byte(uint8_t b) {
crc32_context = ((crc32_context >> 8) & 0x00FFFFFF) ^
crc32_tab[(crc32_context ^ b) & 0xFF];
}
static void crc32_8bytes(uint64_t val) {
crc32_byte((val >> 0) & 0xff);
crc32_byte((val >> 8) & 0xff);
crc32_byte((val >> 16) & 0xff);
crc32_byte((val >> 24) & 0xff);
crc32_byte((val >> 32) & 0xff);
crc32_byte((val >> 40) & 0xff);
crc32_byte((val >> 48) & 0xff);
crc32_byte((val >> 56) & 0xff);
}
static void transparent_crc(uint64_t val) { crc32_8bytes(val); }
#define INT64_MIN (-(9223372036854775807LL) - 1)
#define safe_div_func_int64_t_s_s(_si1, _si2)
\
({
\
int64_t si1 = (_si1);
\
int64_t si2 = (_si2);
\
((((int64_t)(si2)) == ((int64_t)0)) ||
\
((((int64_t)(si1)) == (INT64_MIN)) &&
\
(((int64_t)(si2)) == ((int64_t)-1))))
\
? ((int64_t)(si1))
\
: (((int64_t)(si1)) / ((int64_t)(si2)));
\
})
#define safe_div_func_uint8_t_u_u(_ui1, _ui2)
\
({
\
uint8_t ui1 = (_ui1);
\
uint8_t ui2 = (_ui2);
\
(((uint8_t)(ui2)) == ((uint8_t)0))
\
? ((uint8_t)(ui1))
\
: (((uint8_t)(ui1)) / ((uint8_t)(ui2)));
\
})
//-----------------------------------------------------------------------------
struct {
int32_t a;
} b = {1};
uint16_t c = 1;
void main() {
int d = 0;
crc32_gentab();
int32_t *e = &b.a;
uint64_t f = 8;
printf("%d\n",b.a);
g:
if (*e)
for (c = 0; 0;)
;
else {
int8_t h = 0;
i:
for (; 0; f++)
;
if (f)
goto g;
if (safe_div_func_uint8_t_u_u(safe_div_func_int64_t_s_s(*e, 0), h))
goto i;
}
transparent_crc(c);
printf("checksum = %X\n", crc32_context);
}</pre>
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