* [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions @ 2018-07-24 12:13 Yasmin Beatriz 2018-07-26 1:40 ` David Gibson 0 siblings, 1 reply; 4+ messages in thread From: Yasmin Beatriz @ 2018-07-24 12:13 UTC (permalink / raw) To: qemu-ppc; +Cc: qemu-devel, david, rth After solving a corner case in bcdsub, this patch simplifies the logic of both bcdadd/sub instructions by removing some unnecessary local flags. Signed-off-by: Yasmin Beatriz <yasmins@linux.ibm.com> --- target/ppc/int_helper.c | 33 +++++++++------------------------ 1 file changed, 9 insertions(+), 24 deletions(-) diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c index fa18e6e..b8ac4bb 100644 --- a/target/ppc/int_helper.c +++ b/target/ppc/int_helper.c @@ -2671,16 +2671,14 @@ static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b) return 0; } -static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, +static void bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, int *overflow) { int carry = 0; int i; - int is_zero = 1; for (i = 1; i <= 31; i++) { uint8_t digit = bcd_get_digit(a, i, invalid) + bcd_get_digit(b, i, invalid) + carry; - is_zero &= (digit == 0); if (digit > 9) { carry = 1; digit -= 10; @@ -2689,26 +2687,20 @@ static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, } bcd_put_digit(t, digit, i); - - if (unlikely(*invalid)) { - return -1; - } } *overflow = carry; - return is_zero; } -static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, +static void bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, int *overflow) { int carry = 0; int i; - int is_zero = 1; + for (i = 1; i <= 31; i++) { uint8_t digit = bcd_get_digit(a, i, invalid) - bcd_get_digit(b, i, invalid) + carry; - is_zero &= (digit == 0); if (digit & 0x80) { carry = -1; digit += 10; @@ -2717,14 +2709,9 @@ static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, } bcd_put_digit(t, digit, i); - - if (unlikely(*invalid)) { - return -1; - } } *overflow = carry; - return is_zero; } uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) @@ -2734,25 +2721,25 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) int sgnb = bcd_get_sgn(b); int invalid = (sgna == 0) || (sgnb == 0); int overflow = 0; - int zero = 0; uint32_t cr = 0; ppc_avr_t result = { .u64 = { 0, 0 } }; if (!invalid) { if (sgna == sgnb) { result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); - zero = bcd_add_mag(&result, a, b, &invalid, &overflow); - cr = (sgna > 0) ? CRF_GT : CRF_LT; + bcd_add_mag(&result, a, b, &invalid, &overflow); + cr = bcd_cmp_zero(&result); } else if (bcd_cmp_mag(a, b) > 0) { result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); - zero = bcd_sub_mag(&result, a, b, &invalid, &overflow); + bcd_sub_mag(&result, a, b, &invalid, &overflow); cr = (sgna > 0) ? CRF_GT : CRF_LT; } else if (bcd_cmp_mag(a, b) == 0) { result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(0, ps); - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); + bcd_sub_mag(&result, b, a, &invalid, &overflow); + cr = CRF_EQ; } else { result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgnb, ps); - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); + bcd_sub_mag(&result, b, a, &invalid, &overflow); cr = (sgnb > 0) ? CRF_GT : CRF_LT; } } @@ -2762,8 +2749,6 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) cr = CRF_SO; } else if (overflow) { cr |= CRF_SO; - } else if (zero) { - cr = CRF_EQ; } *r = result; -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions 2018-07-24 12:13 [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions Yasmin Beatriz @ 2018-07-26 1:40 ` David Gibson 2018-07-26 19:44 ` Yasmin Beatriz 0 siblings, 1 reply; 4+ messages in thread From: David Gibson @ 2018-07-26 1:40 UTC (permalink / raw) To: Yasmin Beatriz; +Cc: qemu-ppc, qemu-devel, rth [-- Attachment #1: Type: text/plain, Size: 4850 bytes --] On Tue, Jul 24, 2018 at 12:13:04PM +0000, Yasmin Beatriz wrote: > After solving a corner case in bcdsub, this patch simplifies the logic > of both bcdadd/sub instructions by removing some unnecessary local flags. > > Signed-off-by: Yasmin Beatriz <yasmins@linux.ibm.com> > --- > target/ppc/int_helper.c | 33 +++++++++------------------------ > 1 file changed, 9 insertions(+), 24 deletions(-) > > diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c > index fa18e6e..b8ac4bb 100644 > --- a/target/ppc/int_helper.c > +++ b/target/ppc/int_helper.c > @@ -2671,16 +2671,14 @@ static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b) > return 0; > } > > -static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > +static void bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > int *overflow) > { > int carry = 0; > int i; > - int is_zero = 1; > for (i = 1; i <= 31; i++) { > uint8_t digit = bcd_get_digit(a, i, invalid) + > bcd_get_digit(b, i, invalid) + carry; > - is_zero &= (digit == 0); > if (digit > 9) { > carry = 1; > digit -= 10; > @@ -2689,26 +2687,20 @@ static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > } > > bcd_put_digit(t, digit, i); > - > - if (unlikely(*invalid)) { > - return -1; > - } > } > > *overflow = carry; > - return is_zero; > } > > -static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > +static void bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > int *overflow) > { > int carry = 0; > int i; > - int is_zero = 1; > + > for (i = 1; i <= 31; i++) { > uint8_t digit = bcd_get_digit(a, i, invalid) - > bcd_get_digit(b, i, invalid) + carry; > - is_zero &= (digit == 0); > if (digit & 0x80) { > carry = -1; > digit += 10; > @@ -2717,14 +2709,9 @@ static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > } > > bcd_put_digit(t, digit, i); > - > - if (unlikely(*invalid)) { > - return -1; > - } > } > > *overflow = carry; > - return is_zero; > } > > uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > @@ -2734,25 +2721,25 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > int sgnb = bcd_get_sgn(b); > int invalid = (sgna == 0) || (sgnb == 0); > int overflow = 0; > - int zero = 0; > uint32_t cr = 0; > ppc_avr_t result = { .u64 = { 0, 0 } }; > > if (!invalid) { > if (sgna == sgnb) { > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > - zero = bcd_add_mag(&result, a, b, &invalid, &overflow); > - cr = (sgna > 0) ? CRF_GT : CRF_LT; > + bcd_add_mag(&result, a, b, &invalid, &overflow); > + cr = bcd_cmp_zero(&result); > } else if (bcd_cmp_mag(a, b) > 0) { > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > - zero = bcd_sub_mag(&result, a, b, &invalid, &overflow); > + bcd_sub_mag(&result, a, b, &invalid, &overflow); > cr = (sgna > 0) ? CRF_GT : CRF_LT; > } else if (bcd_cmp_mag(a, b) == 0) { > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(0, ps); > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > + bcd_sub_mag(&result, b, a, &invalid, &overflow); I don't think you actually need the sub here, since you know the result is going to be zero. Although.. in all of the different-sign cases aren't we effectively doing the subtraction twice - once in bcd_cmp_mag() then again in bcd_sub_mag()? > + cr = CRF_EQ; > } else { > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgnb, ps); > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > + bcd_sub_mag(&result, b, a, &invalid, &overflow); > cr = (sgnb > 0) ? CRF_GT : CRF_LT; > } > } > @@ -2762,8 +2749,6 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > cr = CRF_SO; > } else if (overflow) { > cr |= CRF_SO; > - } else if (zero) { > - cr = CRF_EQ; > } > > *r = result; -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions 2018-07-26 1:40 ` David Gibson @ 2018-07-26 19:44 ` Yasmin Beatriz 2018-07-27 0:48 ` David Gibson 0 siblings, 1 reply; 4+ messages in thread From: Yasmin Beatriz @ 2018-07-26 19:44 UTC (permalink / raw) To: David Gibson; +Cc: qemu-ppc, qemu-devel, rth On Thu, Jul 26, 2018 at 11:40:20AM +1000, David Gibson wrote: > On Tue, Jul 24, 2018 at 12:13:04PM +0000, Yasmin Beatriz wrote: > > After solving a corner case in bcdsub, this patch simplifies the logic > > of both bcdadd/sub instructions by removing some unnecessary local flags. > > > > Signed-off-by: Yasmin Beatriz <yasmins@linux.ibm.com> > > --- > > target/ppc/int_helper.c | 33 +++++++++------------------------ > > 1 file changed, 9 insertions(+), 24 deletions(-) > > > > diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c > > index fa18e6e..b8ac4bb 100644 > > --- a/target/ppc/int_helper.c > > +++ b/target/ppc/int_helper.c > > @@ -2671,16 +2671,14 @@ static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b) > > return 0; > > } > > > > -static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > +static void bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > int *overflow) > > { > > int carry = 0; > > int i; > > - int is_zero = 1; > > for (i = 1; i <= 31; i++) { > > uint8_t digit = bcd_get_digit(a, i, invalid) + > > bcd_get_digit(b, i, invalid) + carry; > > - is_zero &= (digit == 0); > > if (digit > 9) { > > carry = 1; > > digit -= 10; > > @@ -2689,26 +2687,20 @@ static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > } > > > > bcd_put_digit(t, digit, i); > > - > > - if (unlikely(*invalid)) { > > - return -1; > > - } > > } > > > > *overflow = carry; > > - return is_zero; > > } > > > > -static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > +static void bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > int *overflow) > > { > > int carry = 0; > > int i; > > - int is_zero = 1; > > + > > for (i = 1; i <= 31; i++) { > > uint8_t digit = bcd_get_digit(a, i, invalid) - > > bcd_get_digit(b, i, invalid) + carry; > > - is_zero &= (digit == 0); > > if (digit & 0x80) { > > carry = -1; > > digit += 10; > > @@ -2717,14 +2709,9 @@ static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > } > > > > bcd_put_digit(t, digit, i); > > - > > - if (unlikely(*invalid)) { > > - return -1; > > - } > > } > > > > *overflow = carry; > > - return is_zero; > > } > > > > uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > @@ -2734,25 +2721,25 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > int sgnb = bcd_get_sgn(b); > > int invalid = (sgna == 0) || (sgnb == 0); > > int overflow = 0; > > - int zero = 0; > > uint32_t cr = 0; > > ppc_avr_t result = { .u64 = { 0, 0 } }; > > > > if (!invalid) { > > if (sgna == sgnb) { > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > > - zero = bcd_add_mag(&result, a, b, &invalid, &overflow); > > - cr = (sgna > 0) ? CRF_GT : CRF_LT; > > + bcd_add_mag(&result, a, b, &invalid, &overflow); > > + cr = bcd_cmp_zero(&result); > > } else if (bcd_cmp_mag(a, b) > 0) { > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > > - zero = bcd_sub_mag(&result, a, b, &invalid, &overflow); > > + bcd_sub_mag(&result, a, b, &invalid, &overflow); > > cr = (sgna > 0) ? CRF_GT : CRF_LT; > > } else if (bcd_cmp_mag(a, b) == 0) { > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(0, ps); > > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > > + bcd_sub_mag(&result, b, a, &invalid, &overflow); > > I don't think you actually need the sub here, since you know the > result is going to be zero. Right. Will fix this in v2. > Although.. in all of the different-sign cases aren't we effectively > doing the subtraction twice - once in bcd_cmp_mag() then again in > bcd_sub_mag()? Actually no, bcd_cmp_mag() compares the magnitude between 'a' and 'b' starting from the most significant digit and returns as soon as it finds a difference between the two of them. It helps to decide whether we're going to perform a - b or b - a. Anyway, I think the following code can make it easier to understand: int magnitude; if (sgna == sgnb) { // same thing } else { magnitude = bdc_cmp_mag(a, b); if (magnitude > 0) { // do a - b } else if (magnitude < 0) { // do b - a } else { // 0 } } > > + cr = CRF_EQ; > > } else { > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgnb, ps); > > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > > + bcd_sub_mag(&result, b, a, &invalid, &overflow); > > cr = (sgnb > 0) ? CRF_GT : CRF_LT; > > } > > } > > @@ -2762,8 +2749,6 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > cr = CRF_SO; > > } else if (overflow) { > > cr |= CRF_SO; > > - } else if (zero) { > > - cr = CRF_EQ; > > } > > > > *r = result; > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions 2018-07-26 19:44 ` Yasmin Beatriz @ 2018-07-27 0:48 ` David Gibson 0 siblings, 0 replies; 4+ messages in thread From: David Gibson @ 2018-07-27 0:48 UTC (permalink / raw) To: Yasmin Beatriz; +Cc: qemu-ppc, qemu-devel, rth [-- Attachment #1: Type: text/plain, Size: 6186 bytes --] On Thu, Jul 26, 2018 at 04:44:43PM -0300, Yasmin Beatriz wrote: > On Thu, Jul 26, 2018 at 11:40:20AM +1000, David Gibson wrote: > > On Tue, Jul 24, 2018 at 12:13:04PM +0000, Yasmin Beatriz wrote: > > > After solving a corner case in bcdsub, this patch simplifies the logic > > > of both bcdadd/sub instructions by removing some unnecessary local flags. > > > > > > Signed-off-by: Yasmin Beatriz <yasmins@linux.ibm.com> > > > --- > > > target/ppc/int_helper.c | 33 +++++++++------------------------ > > > 1 file changed, 9 insertions(+), 24 deletions(-) > > > > > > diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c > > > index fa18e6e..b8ac4bb 100644 > > > --- a/target/ppc/int_helper.c > > > +++ b/target/ppc/int_helper.c > > > @@ -2671,16 +2671,14 @@ static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b) > > > return 0; > > > } > > > > > > -static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > +static void bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > int *overflow) > > > { > > > int carry = 0; > > > int i; > > > - int is_zero = 1; > > > for (i = 1; i <= 31; i++) { > > > uint8_t digit = bcd_get_digit(a, i, invalid) + > > > bcd_get_digit(b, i, invalid) + carry; > > > - is_zero &= (digit == 0); > > > if (digit > 9) { > > > carry = 1; > > > digit -= 10; > > > @@ -2689,26 +2687,20 @@ static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > } > > > > > > bcd_put_digit(t, digit, i); > > > - > > > - if (unlikely(*invalid)) { > > > - return -1; > > > - } > > > } > > > > > > *overflow = carry; > > > - return is_zero; > > > } > > > > > > -static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > +static void bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > int *overflow) > > > { > > > int carry = 0; > > > int i; > > > - int is_zero = 1; > > > + > > > for (i = 1; i <= 31; i++) { > > > uint8_t digit = bcd_get_digit(a, i, invalid) - > > > bcd_get_digit(b, i, invalid) + carry; > > > - is_zero &= (digit == 0); > > > if (digit & 0x80) { > > > carry = -1; > > > digit += 10; > > > @@ -2717,14 +2709,9 @@ static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *invalid, > > > } > > > > > > bcd_put_digit(t, digit, i); > > > - > > > - if (unlikely(*invalid)) { > > > - return -1; > > > - } > > > } > > > > > > *overflow = carry; > > > - return is_zero; > > > } > > > > > > uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > > @@ -2734,25 +2721,25 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > > int sgnb = bcd_get_sgn(b); > > > int invalid = (sgna == 0) || (sgnb == 0); > > > int overflow = 0; > > > - int zero = 0; > > > uint32_t cr = 0; > > > ppc_avr_t result = { .u64 = { 0, 0 } }; > > > > > > if (!invalid) { > > > if (sgna == sgnb) { > > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > > > - zero = bcd_add_mag(&result, a, b, &invalid, &overflow); > > > - cr = (sgna > 0) ? CRF_GT : CRF_LT; > > > + bcd_add_mag(&result, a, b, &invalid, &overflow); > > > + cr = bcd_cmp_zero(&result); > > > } else if (bcd_cmp_mag(a, b) > 0) { > > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgna, ps); > > > - zero = bcd_sub_mag(&result, a, b, &invalid, &overflow); > > > + bcd_sub_mag(&result, a, b, &invalid, &overflow); > > > cr = (sgna > 0) ? CRF_GT : CRF_LT; > > > } else if (bcd_cmp_mag(a, b) == 0) { > > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(0, ps); > > > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > > > + bcd_sub_mag(&result, b, a, &invalid, &overflow); > > > > I don't think you actually need the sub here, since you know the > > result is going to be zero. > > Right. Will fix this in v2. > > > Although.. in all of the different-sign cases aren't we effectively > > doing the subtraction twice - once in bcd_cmp_mag() then again in > > bcd_sub_mag()? > > Actually no, bcd_cmp_mag() compares the magnitude between 'a' and 'b' > starting from the most significant digit and returns as soon as it finds > a difference between the two of them. It helps to decide whether we're > going to perform a - b or b - a. Ah, good point. > Anyway, I think the following code can make it easier to understand: > > int magnitude; > if (sgna == sgnb) { > // same thing > } else { > magnitude = bdc_cmp_mag(a, b); > if (magnitude > 0) { > // do a - b > } else if (magnitude < 0) { > // do b - a > } else { > // 0 > } > } Yes, I think that's a good idea. > > > > + cr = CRF_EQ; > > > } else { > > > result.u8[BCD_DIG_BYTE(0)] = bcd_preferred_sgn(sgnb, ps); > > > - zero = bcd_sub_mag(&result, b, a, &invalid, &overflow); > > > + bcd_sub_mag(&result, b, a, &invalid, &overflow); > > > cr = (sgnb > 0) ? CRF_GT : CRF_LT; > > > } > > > } > > > @@ -2762,8 +2749,6 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t ps) > > > cr = CRF_SO; > > > } else if (overflow) { > > > cr |= CRF_SO; > > > - } else if (zero) { > > > - cr = CRF_EQ; > > > } > > > > > > *r = result; > > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-07-27 0:48 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-07-24 12:13 [Qemu-devel] [PATCH] target/ppc: simplify bcdadd/sub functions Yasmin Beatriz 2018-07-26 1:40 ` David Gibson 2018-07-26 19:44 ` Yasmin Beatriz 2018-07-27 0:48 ` David Gibson
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