| Message ID | 20230822093712.38922-3-philmd@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | tcg: Document *swap/deposit helpers | expand |
On 8/22/23 02:37, Philippe Mathieu-Daudé wrote: > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > tcg/tcg-op.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c > index f164ddc95e..e6b0d74a46 100644 > --- a/tcg/tcg-op.c > +++ b/tcg/tcg-op.c > @@ -1061,6 +1061,11 @@ void tcg_gen_bswap16_i32(TCGv_i32 ret, TCGv_i32 arg, int flags) > } > } > > +/* > + * bswap32_i32: 32-bit byte swap on a 32-bit value. > + * > + * Byte pattern: bswap32_i32(abcd) -> dcba > + */ Ok. > void tcg_gen_bswap32_i32(TCGv_i32 ret, TCGv_i32 arg) > { > if (TCG_TARGET_HAS_bswap32_i32) { > @@ -1776,6 +1781,13 @@ void tcg_gen_bswap16_i64(TCGv_i64 ret, TCGv_i64 arg, int flags) > } > } > > +/* > + * bswap32_i64: 32-bit byte swap on the low bits of a 64-bit value. > + * > + * Byte pattern: bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OZ) > + * bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS) > + * bswap32_i64(xxxxabcd) -> xxxxdcba > + */ Again, TCG_BSWAP_IZ. r~
On 22/8/23 18:00, Richard Henderson wrote: > On 8/22/23 02:37, Philippe Mathieu-Daudé wrote: >> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> >> --- >> tcg/tcg-op.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> +/* >> + * bswap32_i64: 32-bit byte swap on the low bits of a 64-bit value. >> + * >> + * Byte pattern: bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OZ) >> + * bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS) >> + * bswap32_i64(xxxxabcd) -> xxxxdcba >> + */ > > Again, TCG_BSWAP_IZ. Whether TCG_BSWAP_IZ is set or not doesn't change the result, at the end we have: bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OS not set) bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS set)
On 8/23/23 06:14, Philippe Mathieu-Daudé wrote: > On 22/8/23 18:00, Richard Henderson wrote: >> On 8/22/23 02:37, Philippe Mathieu-Daudé wrote: >>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> >>> --- >>> tcg/tcg-op.c | 12 ++++++++++++ >>> 1 file changed, 12 insertions(+) > > >>> +/* >>> + * bswap32_i64: 32-bit byte swap on the low bits of a 64-bit value. >>> + * >>> + * Byte pattern: bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OZ) >>> + * bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS) >>> + * bswap32_i64(xxxxabcd) -> xxxxdcba >>> + */ >> >> Again, TCG_BSWAP_IZ. > > Whether TCG_BSWAP_IZ is set or not doesn't change the result, at the > end we have: > > bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OS not set) > bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS set) It changes the input: not 'x' but '.'. r~
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c index f164ddc95e..e6b0d74a46 100644 --- a/tcg/tcg-op.c +++ b/tcg/tcg-op.c @@ -1061,6 +1061,11 @@ void tcg_gen_bswap16_i32(TCGv_i32 ret, TCGv_i32 arg, int flags) } } +/* + * bswap32_i32: 32-bit byte swap on a 32-bit value. + * + * Byte pattern: bswap32_i32(abcd) -> dcba + */ void tcg_gen_bswap32_i32(TCGv_i32 ret, TCGv_i32 arg) { if (TCG_TARGET_HAS_bswap32_i32) { @@ -1776,6 +1781,13 @@ void tcg_gen_bswap16_i64(TCGv_i64 ret, TCGv_i64 arg, int flags) } } +/* + * bswap32_i64: 32-bit byte swap on the low bits of a 64-bit value. + * + * Byte pattern: bswap32_i64(xxxxabcd) -> ....dcba (TCG_BSWAP_OZ) + * bswap32_i64(xxxxabcd) -> ssssdcba (TCG_BSWAP_OS) + * bswap32_i64(xxxxabcd) -> xxxxdcba + */ void tcg_gen_bswap32_i64(TCGv_i64 ret, TCGv_i64 arg, int flags) { /* Only one extension flag may be present. */
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- tcg/tcg-op.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)