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Merged
sigilante merged 1 commit into from
May 30, 2026
Merged

Finish rot/rotg/rotm to the BLAS reference (C8 part 2) #19

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9 changes: 9 additions & 0 deletions Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,15 @@ BLAS_SRCS = \
$(BLAS_SRC_DIR_L1)/cdotc.c \
$(BLAS_SRC_DIR_L1)/scnrm2.c \
$(BLAS_SRC_DIR_L1)/csrot.c \
$(BLAS_SRC_DIR_L1)/srot.c \
$(BLAS_SRC_DIR_L1)/drot.c \
$(BLAS_SRC_DIR_L1)/hrot.c \
$(BLAS_SRC_DIR_L1)/srotg.c \
$(BLAS_SRC_DIR_L1)/drotg.c \
$(BLAS_SRC_DIR_L1)/hrotg.c \
$(BLAS_SRC_DIR_L1)/srotm.c \
$(BLAS_SRC_DIR_L1)/drotm.c \
$(BLAS_SRC_DIR_L1)/hrotm.c \
$(BLAS_SRC_DIR_L2)/sgemv.c \
$(BLAS_SRC_DIR_L2)/dgemv.c \
$(BLAS_SRC_DIR_L2)/hgemv.c \
Expand Down
33 changes: 12 additions & 21 deletions src/blas/level1/drot.c
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@@ -1,23 +1,14 @@
void drot(const uint64_t N, float64_t *X, const uint64_t incX, float64_t *Y, const uint64_t incY, const float64_t c, const float64_t s, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
float64_t tmp;
#include "softblas.h"

if (c != SB_REAL64_ONE || s != SB_REAL64_ZERO) {
if (incX == 1 && incY == 1) {
for (uint64_t i=0; i != N; i++) {
tmp = f64_add(f64_mul(c, X[i]), f64_mul(s, Y[i]));
Y[i] = f64_sub(f64_mul(c, Y[i]), f64_mul(s, X[i]));
X[i] = tmp;
}
}
else
{
for (uint64_t i=N; i; i--, Y += incY, X += incX)
{
tmp = f64_add(f64_mul(c, *X), f64_mul(s, *Y));
*Y = f64_sub(f64_mul(c, *Y), f64_mul(s, *X));
*X = tmp;
}
}
// Apply a plane rotation: [x_i; y_i] <- [c s; -s c] [x_i; y_i].
void drot(const uint64_t N, float64_t *X, const uint64_t incX, float64_t *Y, const uint64_t incY, const float64_t c, const float64_t s, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
uint64_t iX = 0, iY = 0;
for (uint64_t i = 0; i < N; i++) {
float64_t tmp = f64_add(f64_mul(c, X[iX]), f64_mul(s, Y[iY]));
Y[iY] = nan_unify_d(f64_sub(f64_mul(c, Y[iY]), f64_mul(s, X[iX])));
X[iX] = nan_unify_d(tmp);
iX += incX;
iY += incY;
}
}
}
53 changes: 29 additions & 24 deletions src/blas/level1/drotg.c
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@@ -1,30 +1,35 @@
#include "softblas.h"

// Construct a Givens rotation that zeroes b: returns c, s, and overwrites
// a with r = +/-sqrt(a^2+b^2) and b with the reconstruction scalar z.
// (The SoftFloat comparison/abs macros do not parenthesize their argument,
// so every operand here is first loaded into a plain local.)
void drotg(float64_t *a, float64_t *b, float64_t *c, float64_t *s, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
float64_t roe, scal, r, z, aa, ab, t0, t1;
const float64_t ZERO = { SB_REAL64_ZERO };
const float64_t ONE = { SB_REAL64_ONE };
const float64_t NEG = { SB_REAL64_NEGONE };

aa = f64_abs(*a);
ab = f64_abs(*b);
if f64_gt(aa, ab) roe = *a;
else roe = *b;
scal = f64_add(aa, ab);
if f64_ne(scal, SB_REAL64_ZERO)
{
t0 = f64_div(aa, scal); t1 = f64_div(ab, scal);
r = f64_mul(scal, f64_sqrt(f64_add(f64_mul(t0, t0), f64_mul(t1, t1))));
if f64_le(roe, SB_REAL64_ZERO) r = f64_neg(r);
*c = f64_div(*a, r);
*s = f64_div(*b, r);
if f64_gt(aa, ab) z = *s;
else if f64_ne(*c, SB_REAL64_ZERO) z = f64_div(SB_REAL64_ONE, *c);
else z = SB_REAL64_ONE;
*a = r;
*b = z;
}
else
{
*c = SB_REAL64_ONE;
*s = *a = *b = SB_REAL64_ZERO;
}
float64_t A = *a, B = *b;
float64_t absA = f64_abs(A), absB = f64_abs(B);
float64_t roe = f64_gt(absA, absB) ? A : B;
float64_t scale = f64_add(absA, absB);
float64_t r, z;

if (f64_eq(scale, ZERO)) {
*c = ONE; *s = ZERO; r = ZERO; z = ZERO;
} else {
float64_t as = f64_div(A, scale);
float64_t bs = f64_div(B, scale);
r = f64_mul(scale, f64_sqrt(f64_add(f64_mul(as, as), f64_mul(bs, bs))));
r = f64_mul(f64_lt(roe, ZERO) ? NEG : ONE, r); // sign(roe) * |r|
*c = f64_div(A, r);
*s = f64_div(B, r);
float64_t C = *c, S = *s;
z = ONE;
if (f64_gt(absA, absB)) z = S;
if (f64_ge(absB, absA) && f64_ne(C, ZERO)) z = f64_div(ONE, C);
}
*a = r;
*b = z;
}
110 changes: 26 additions & 84 deletions src/blas/level1/drotm.c
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@@ -1,90 +1,32 @@
#include "softblas.h"

// Apply a modified Givens rotation H (selected by the flag P[0]) to the
// pair of vectors X, Y. H is built from P[1..4] as in the reference SROTM.
void drotm(const uint64_t N, float64_t *X, const uint64_t incX, float64_t *Y, const uint64_t incY, const float64_t *P, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
uint64_t i;
const float64_t flag = *P;
float64_t h11, h21, h12, h22, w, z;
const float64_t flag = P[0];
const float64_t NEGTWO = { SB_REAL64_NEGTWO };
const float64_t NEGONE = { SB_REAL64_NEGONE };
const float64_t ZERO = { SB_REAL64_ZERO };
const float64_t ONE = { SB_REAL64_ONE };

if f64_eq(flag, SB_REAL64_NEGTWO) return;
if (f64_eq(flag, SB_REAL64_NEGONE))
{
h11 = P[1]; h21 = P[2]; h12 = P[3]; h22 = P[4];
if (incX == 1 && incY == 1)
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X++ = f64_add(f64_mul(w, h11), f64_mul(z, h12));
*Y++ = f64_add(f64_mul(w, h21), f64_mul(z, h22));
}
}
else
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X = f64_add(f64_mul(w, h11), f64_mul(z, h12));
*Y = f64_add(f64_mul(w, h21), f64_mul(z, h22));
X += incX;
Y += incY;
}
}
}
else if (f64_eq(flag, SB_REAL64_ZERO))
{
h21 = P[2];
h12 = P[3];
if (incX == 1 && incY == 1)
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X++ = f64_add(w, f64_mul(z, h12));
*Y++ = f64_add(f64_mul(w, h21), z);
}
}
else
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X = f64_add(w, f64_mul(z, h12));
*Y = f64_add(f64_mul(w, h21), z);
X += incX;
Y += incY;
}
}
}
else if (f64_eq(flag, SB_REAL64_ONE))
{
h11 = P[1];
h22 = P[4];
if (incX == 1 && incY == 1)
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X++ = f64_add(f64_mul(w, h11), z);
*Y++ = f64_sub(f64_mul(z, h22), w);
}
}
else
{
for (i = N; i; i--)
{
w = *X;
z = *Y;
*X = f64_add(f64_mul(w, h11), z);
*Y = f64_sub(f64_mul(z, h22), w);
X += incX;
Y += incY;
}
}
}
if (f64_eq(flag, NEGTWO)) return;

float64_t h11, h21, h12, h22;
if (f64_eq(flag, NEGONE)) {
h11 = P[1]; h21 = P[2]; h12 = P[3]; h22 = P[4];
} else if (f64_eq(flag, ZERO)) {
h11 = ONE; h21 = P[2]; h12 = P[3]; h22 = ONE;
} else { /* flag == 1 */
h11 = P[1]; h21 = NEGONE; h12 = ONE; h22 = P[4];
}

uint64_t iX = 0, iY = 0;
for (uint64_t i = 0; i < N; i++) {
float64_t w = X[iX], z = Y[iY];
X[iX] = nan_unify_d(f64_add(f64_mul(w, h11), f64_mul(z, h12)));
Y[iY] = nan_unify_d(f64_add(f64_mul(w, h21), f64_mul(z, h22)));
iX += incX;
iY += incY;
}
}
31 changes: 11 additions & 20 deletions src/blas/level1/hrot.c
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@@ -1,23 +1,14 @@
void hrot(const uint16_t N, float16_t *X, const uint16_t incX, float16_t *Y, const uint16_t incY, const float16_t c, const float16_t s) {
_set_rounding(rndMode);
float16_t tmp;
#include "softblas.h"

if (c != SB_REAL32_ONE || s != SB_REAL32_ZERO) {
if (incX == 1 && incY == 1) {
for (uint64_t i=0; i != N; i++) {
tmp = f16_add(f16_mul(c, X[i]), f16_mul(s, Y[i]));
Y[i] = f16_sub(f16_mul(c, Y[i]), f16_mul(s, X[i]));
X[i] = tmp;
}
}
else
{
for (uint64_t i=N; i; i--, Y += incY, X += incX)
{
tmp = f16_add(f16_mul(c, *X), f16_mul(s, *Y));
*Y = f16_sub(f16_mul(c, *Y), f16_mul(s, *X));
*X = tmp;
}
}
// Apply a plane rotation: [x_i; y_i] <- [c s; -s c] [x_i; y_i].
void hrot(const uint64_t N, float16_t *X, const uint64_t incX, float16_t *Y, const uint64_t incY, const float16_t c, const float16_t s, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
uint64_t iX = 0, iY = 0;
for (uint64_t i = 0; i < N; i++) {
float16_t tmp = f16_add(f16_mul(c, X[iX]), f16_mul(s, Y[iY]));
Y[iY] = nan_unify_h(f16_sub(f16_mul(c, Y[iY]), f16_mul(s, X[iX])));
X[iX] = nan_unify_h(tmp);
iX += incX;
iY += incY;
}
}
53 changes: 29 additions & 24 deletions src/blas/level1/hrotg.c
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@@ -1,30 +1,35 @@
#include "softblas.h"

// Construct a Givens rotation that zeroes b: returns c, s, and overwrites
// a with r = +/-sqrt(a^2+b^2) and b with the reconstruction scalar z.
// (The SoftFloat comparison/abs macros do not parenthesize their argument,
// so every operand here is first loaded into a plain local.)
void hrotg(float16_t *a, float16_t *b, float16_t *c, float16_t *s, const uint_fast8_t rndMode) {
_set_rounding(rndMode);
float16_t roe, scal, r, z, aa, ab, t0, t1;
const float16_t ZERO = { SB_REAL16_ZERO };
const float16_t ONE = { SB_REAL16_ONE };
const float16_t NEG = { SB_REAL16_NEGONE };

aa = f16_abs(*a);
ab = f16_abs(*b);
if f16_gt(aa, ab) roe = *a;
else roe = *b;
scal = f16_add(aa, ab);
if f16_ne(scal, SB_REAL16_ZERO)
{
t0 = f16_div(aa, scal); t1 = f16_div(ab, scal);
r = f16_mul(scal, f16_sqrt(f16_add(f16_mul(t0, t0), f16_mul(t1, t1))));
if f16_le(roe, SB_REAL16_ZERO) r = f16_neg(r);
*c = f16_div(*a, r);
*s = f16_div(*b, r);
if f16_gt(aa, ab) z = *s;
else if f16_ne(*c, SB_REAL16_ZERO) z = f16_div(SB_REAL16_ONE, *c);
else z = SB_REAL16_ONE;
*a = r;
*b = z;
}
else
{
*c = SB_REAL16_ONE;
*s = *a = *b = SB_REAL16_ZERO;
}
float16_t A = *a, B = *b;
float16_t absA = f16_abs(A), absB = f16_abs(B);
float16_t roe = f16_gt(absA, absB) ? A : B;
float16_t scale = f16_add(absA, absB);
float16_t r, z;

if (f16_eq(scale, ZERO)) {
*c = ONE; *s = ZERO; r = ZERO; z = ZERO;
} else {
float16_t as = f16_div(A, scale);
float16_t bs = f16_div(B, scale);
r = f16_mul(scale, f16_sqrt(f16_add(f16_mul(as, as), f16_mul(bs, bs))));
r = f16_mul(f16_lt(roe, ZERO) ? NEG : ONE, r); // sign(roe) * |r|
*c = f16_div(A, r);
*s = f16_div(B, r);
float16_t C = *c, S = *s;
z = ONE;
if (f16_gt(absA, absB)) z = S;
if (f16_ge(absB, absA) && f16_ne(C, ZERO)) z = f16_div(ONE, C);
}
*a = r;
*b = z;
}
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