From 431b1ee0e00345dda0bf4b8d2b60ea7d5e6feeab Mon Sep 17 00:00:00 2001 From: Torbjorn Granlund Date: Tue, 7 Jul 1992 19:58:52 +0000 Subject: [PATCH] *** empty log message *** From-SVN: r1504 --- gcc/libgcc2.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 101 insertions(+), 1 deletion(-) diff --git a/gcc/libgcc2.c b/gcc/libgcc2.c index 8e9ed05..8c70133 100644 --- a/gcc/libgcc2.c +++ b/gcc/libgcc2.c @@ -92,7 +92,7 @@ typedef union DItype ll; } DIunion; -#if defined (L_udivmoddi4) || defined (L_muldi3) +#if defined (L_udivmoddi4) || defined (L_muldi3) || defined (L_udiv_using_sdiv) #include "longlong.h" @@ -269,6 +269,106 @@ __muldi3 (u, v) } #endif +#ifdef L_udiv_using_sdiv +USItype +__udiv_using_sdiv (rp, a1, a0, d) + USItype *rp, a1, a0, d; +{ + USItype q, r; + USItype c0, c1, b1; + + if ((SItype) d >= 0) + { + if (a1 < d - a1 - (a0 >> 31)) + { + /* dividend, divisor, and quotient are nonnegative */ + sdiv_qrnnd (q, r, a1, a0, d); + } + else + { + /* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */ + sub_ddmmss (c1, c0, a1, a0, d >> 1, d << 31); + /* Divide (c1*2^32 + c0) by d */ + sdiv_qrnnd (q, r, c1, c0, d); + /* Add 2^31 to quotient */ + q += 1 << 31; + } + } + else + { + b1 = d >> 1; /* d/2, between 2^30 and 2^31 - 1 */ + c1 = a1 >> 1; /* A/2 */ + c0 = (a1 << 31) + (a0 >> 1); + + if (a1 < b1) /* A < 2^32*b1, so A/2 < 2^31*b1 */ + { + sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */ + + r = 2*r + (a0 & 1); /* Remainder from A/(2*b1) */ + if ((d & 1) != 0) + { + if (r >= q) + r = r - q; + else if (q - r <= d) + { + r = r - q + d; + q--; + } + else + { + r = r - q + 2*d; + q -= 2; + } + } + } + else if (c1 < b1) /* So 2^31 <= (A/2)/b1 < 2^32 */ + { + c1 = (b1 - 1) - c1; + c0 = ~c0; /* logical NOT */ + + sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */ + + q = ~q; /* (A/2)/b1 */ + r = (b1 - 1) - r; + + r = 2*r + (a0 & 1); /* A/(2*b1) */ + + if ((d & 1) != 0) + { + if (r >= q) + r = r - q; + else if (q - r <= d) + { + r = r - q + d; + q--; + } + else + { + r = r - q + 2*d; + q -= 2; + } + } + } + else /* Implies c1 = b1 */ + { /* Hence a1 = d - 1 = 2*b1 - 1 */ + if (a0 >= -d) + { + q = -1; + r = a0 + d; + } + else + { + q = -2; + r = a0 + 2*d; + } + } + } + + *rp = r; + return q; +} +#endif + #ifdef L_udivmoddi4 static const UQItype __clz_tab[] = { -- 2.7.4