https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108941
Bug ID: 108941
Summary: Error: operand type mismatch for `shr' with binutils
master
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: marxin at gcc dot gnu.org
CC: jbeulich at suse dot com
Target Milestone: ---
Since the following binutils revision:
commit c34d1cc9200ae24dc7572aaf77d80276c0490e9b
Author: Jan Beulich <jbeul...@suse.com>
Date: Fri Feb 24 13:56:57 2023 +0100
x86: restrict insn templates accepting negative 8-bit immediates
I noticed the following rejected code (reduced from ffmpeg-4 package):
$ cat libavformat.i
void av_log();
typedef signed char __int8_t;
typedef unsigned char __uint8_t;
typedef unsigned int __uint32_t;
typedef __int8_t int8_t;
typedef __uint8_t uint8_t;
typedef __uint32_t uint32_t;
typedef struct AVCodecParameters {
uint8_t *extradata;
int extradata_size;
} AVCodecParameters;
static inline uint32_t NEG_USR32(uint32_t a, int8_t s) {
__asm__("shrl %1, %0\n\t" : "+r"(a) : "ic"((uint8_t)(-s)));
return a;
}
typedef struct GetBitContext {
} GetBitContext;
static inline unsigned int get_bits(GetBitContext *s, int n) {
register unsigned int tmp;
unsigned int __attribute__((unused)) re_cache;
tmp = NEG_USR32(re_cache, n);
return tmp;
};
typedef struct AVOption {
} AVOption;
typedef struct AVOutputFormat {
int (*init)(struct AVFormatContext *);
} AVOutputFormat;
typedef struct AVStream {
AVCodecParameters *codecpar;
} AVStream;
typedef struct AVProgram {
void *priv_data;
AVStream **streams;
} AVFormatContext;
typedef struct ADTSContext {
} ADTSContext;
static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts,
const uint8_t *buf, int size) {
GetBitContext gb;
if (get_bits(&gb, 1)) {
av_log(s, 16, "Extension flag is not allowed in ADTS\n");
}
}
static int adts_init(AVFormatContext *s) {
ADTSContext *adts = s->priv_data;
AVCodecParameters *par = s->streams[0]->codecpar;
return adts_decode_extradata(s, adts, par->extradata, par->extradata_size);
}
static const AVOption options[] = {
};
AVOutputFormat ff_adts_muxer = {
.init = adts_init,
};
$ gcc libavformat.i -w -S -O2 && grep shr libavformat.s &&
/home/marxin/Programming/binutils/objdir/gas/as-new libavformat.s
shrl $-1, %eax
libavformat.i: Assembler messages:
libavformat.i:14: Error: operand type mismatch for `shr'
So we emit -1 even though the user used cast to uint8_t: ((uint8_t)(-s))
