[MIPS] Compiler crash when using -O3 #134916
Description
Using clang version 20.1.2
clang -target "mipsel-w64-windows-gnu" -c test.cpp -O3
typedef unsigned int size_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned uint32_t;
typedef unsigned long long uint64_t;
typedef unsigned int uintptr_t;
typedef signed char int8_t;
typedef short int16_t;
typedef int int32_t;
typedef long long int64_t;
size_t readULEB128(const uint8_t **data);
// read a pointer encoded value and advance pointer
static uintptr_t readEncodedPointer(const uint8_t **data, uint8_t encoding) {
const uint8_t *p = *data;
uintptr_t result = 0;
// first get value
switch (encoding & 0x0F) {
case 0x01:
result = readULEB128(&p);
break;
case 0x0A:
result = *((const int16_t *)p);
p += sizeof(int16_t);
break;
case 0x0B:
result = *((const int32_t *)p);
p += sizeof(int32_t);
break;
case 0x0C:
result = *((const int64_t *)p);
p += sizeof(int64_t);
break;
default:
// not supported
return 0;
}
*data = p;
return result;
}
int __gcc_personality_v0(const uint8_t* lsda)
{
uint8_t callSiteEncoding = *lsda++;
const uint8_t *p = 0;
while (1) {
uintptr_t start = readEncodedPointer(&p, callSiteEncoding);
size_t length = readEncodedPointer(&p, callSiteEncoding);
size_t landingPad = readEncodedPointer(&p, callSiteEncoding);
readULEB128(&p); // action value not used for C code
}
// No landing pad found, continue unwinding.
return 0;
}
gives
fatal error: error in backend: Not supported instr: <MCInst 45 <MCOperand Imm:0>>
Possible workaround: add -O0