diff options
Diffstat (limited to 'lib/ccan/tally/tally.c')
| -rw-r--r-- | lib/ccan/tally/tally.c | 52 |
1 files changed, 26 insertions, 26 deletions
diff --git a/lib/ccan/tally/tally.c b/lib/ccan/tally/tally.c index 4e8876cc4a..a6d66b6688 100644 --- a/lib/ccan/tally/tally.c +++ b/lib/ccan/tally/tally.c @@ -219,36 +219,36 @@ static unsigned fls64(uint64_t val) /* This is stolen straight from Hacker's Delight. */ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v) { - const uint64_t b = 4294967296ULL; // Number base (32 bits). - uint32_t un[4], // Dividend and divisor - vn[2]; // normalized and broken - // up into halfwords. - uint32_t q[2]; // Quotient as halfwords. - uint64_t un1, un0, // Dividend and divisor - vn0; // as fullwords. - uint64_t qhat; // Estimated quotient digit. - uint64_t rhat; // A remainder. - uint64_t p; // Product of two digits. + const uint64_t b = 4294967296ULL; /* Number base (32 bits). */ + uint32_t un[4], /* Dividend and divisor */ + vn[2]; /* normalized and broken */ + /* up into halfwords. */ + uint32_t q[2]; /* Quotient as halfwords. */ + uint64_t un1, un0, /* Dividend and divisor */ + vn0; /* as fullwords. */ + uint64_t qhat; /* Estimated quotient digit. */ + uint64_t rhat; /* A remainder. */ + uint64_t p; /* Product of two digits. */ int64_t s, i, j, t, k; - if (u1 >= v) // If overflow, return the largest - return (uint64_t)-1; // possible quotient. + if (u1 >= v) /* If overflow, return the largest */ + return (uint64_t)-1; /* possible quotient. */ - s = 64 - fls64(v); // 0 <= s <= 63. - vn0 = v << s; // Normalize divisor. - vn[1] = vn0 >> 32; // Break divisor up into - vn[0] = vn0 & 0xFFFFFFFF; // two 32-bit halves. + s = 64 - fls64(v); /* 0 <= s <= 63. */ + vn0 = v << s; /* Normalize divisor. */ + vn[1] = vn0 >> 32; /* Break divisor up into */ + vn[0] = vn0 & 0xFFFFFFFF; /* two 32-bit halves. */ // Shift dividend left. un1 = ((u1 << s) | (u0 >> (64 - s))) & (-s >> 63); un0 = u0 << s; - un[3] = un1 >> 32; // Break dividend up into - un[2] = un1; // four 32-bit halfwords - un[1] = un0 >> 32; // Note: storing into - un[0] = un0; // halfwords truncates. + un[3] = un1 >> 32; /* Break dividend up into */ + un[2] = un1; /* four 32-bit halfwords */ + un[1] = un0 >> 32; /* Note: storing into */ + un[0] = un0; /* halfwords truncates. */ for (j = 1; j >= 0; j--) { - // Compute estimate qhat of q[j]. + /* Compute estimate qhat of q[j]. */ qhat = (un[j+2]*b + un[j+1])/vn[1]; rhat = (un[j+2]*b + un[j+1]) - qhat*vn[1]; again: @@ -258,7 +258,7 @@ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v) if (rhat < b) goto again; } - // Multiply and subtract. + /* Multiply and subtract. */ k = 0; for (i = 0; i < 2; i++) { p = qhat*vn[i]; @@ -269,9 +269,9 @@ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v) t = un[j+2] - k; un[j+2] = t; - q[j] = qhat; // Store quotient digit. - if (t < 0) { // If we subtracted too - q[j] = q[j] - 1; // much, add back. + q[j] = qhat; /* Store quotient digit. */ + if (t < 0) { /* If we subtracted too */ + q[j] = q[j] - 1; /* much, add back. */ k = 0; for (i = 0; i < 2; i++) { t = un[i+j] + vn[i] + k; @@ -280,7 +280,7 @@ static uint64_t divlu64(uint64_t u1, uint64_t u0, uint64_t v) } un[j+2] = un[j+2] + k; } - } // End j. + } /* End j. */ return q[1]*b + q[0]; } |