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-rw-r--r--arch/powerpc/math-emu/udivmodti4.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/arch/powerpc/math-emu/udivmodti4.c b/arch/powerpc/math-emu/udivmodti4.c
new file mode 100644
index 000000000..1e52633dc
--- /dev/null
+++ b/arch/powerpc/math-emu/udivmodti4.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+/* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */
+
+#include <math-emu/soft-fp.h>
+
+#undef count_leading_zeros
+#define count_leading_zeros __FP_CLZ
+
+void
+_fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2],
+ _FP_W_TYPE n1, _FP_W_TYPE n0,
+ _FP_W_TYPE d1, _FP_W_TYPE d0)
+{
+ _FP_W_TYPE q0, q1, r0, r1;
+ _FP_I_TYPE b, bm;
+
+ if (d1 == 0)
+ {
+#if !UDIV_NEEDS_NORMALIZATION
+ if (d0 > n1)
+ {
+ /* 0q = nn / 0D */
+
+ udiv_qrnnd (q0, n0, n1, n0, d0);
+ q1 = 0;
+
+ /* Remainder in n0. */
+ }
+ else
+ {
+ /* qq = NN / 0d */
+
+ if (d0 == 0)
+ d0 = 1 / d0; /* Divide intentionally by zero. */
+
+ udiv_qrnnd (q1, n1, 0, n1, d0);
+ udiv_qrnnd (q0, n0, n1, n0, d0);
+
+ /* Remainder in n0. */
+ }
+
+ r0 = n0;
+ r1 = 0;
+
+#else /* UDIV_NEEDS_NORMALIZATION */
+
+ if (d0 > n1)
+ {
+ /* 0q = nn / 0D */
+
+ count_leading_zeros (bm, d0);
+
+ if (bm != 0)
+ {
+ /* Normalize, i.e. make the most significant bit of the
+ denominator set. */
+
+ d0 = d0 << bm;
+ n1 = (n1 << bm) | (n0 >> (_FP_W_TYPE_SIZE - bm));
+ n0 = n0 << bm;
+ }
+
+ udiv_qrnnd (q0, n0, n1, n0, d0);
+ q1 = 0;
+
+ /* Remainder in n0 >> bm. */
+ }
+ else
+ {
+ /* qq = NN / 0d */
+
+ if (d0 == 0)
+ d0 = 1 / d0; /* Divide intentionally by zero. */
+
+ count_leading_zeros (bm, d0);
+
+ if (bm == 0)
+ {
+ /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
+ conclude (the most significant bit of n1 is set) /\ (the
+ leading quotient digit q1 = 1).
+
+ This special case is necessary, not an optimization.
+ (Shifts counts of SI_TYPE_SIZE are undefined.) */
+
+ n1 -= d0;
+ q1 = 1;
+ }
+ else
+ {
+ _FP_W_TYPE n2;
+
+ /* Normalize. */
+
+ b = _FP_W_TYPE_SIZE - bm;
+
+ d0 = d0 << bm;
+ n2 = n1 >> b;
+ n1 = (n1 << bm) | (n0 >> b);
+ n0 = n0 << bm;
+
+ udiv_qrnnd (q1, n1, n2, n1, d0);
+ }
+
+ /* n1 != d0... */
+
+ udiv_qrnnd (q0, n0, n1, n0, d0);
+
+ /* Remainder in n0 >> bm. */
+ }
+
+ r0 = n0 >> bm;
+ r1 = 0;
+#endif /* UDIV_NEEDS_NORMALIZATION */
+ }
+ else
+ {
+ if (d1 > n1)
+ {
+ /* 00 = nn / DD */
+
+ q0 = 0;
+ q1 = 0;
+
+ /* Remainder in n1n0. */
+ r0 = n0;
+ r1 = n1;
+ }
+ else
+ {
+ /* 0q = NN / dd */
+
+ count_leading_zeros (bm, d1);
+ if (bm == 0)
+ {
+ /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
+ conclude (the most significant bit of n1 is set) /\ (the
+ quotient digit q0 = 0 or 1).
+
+ This special case is necessary, not an optimization. */
+
+ /* The condition on the next line takes advantage of that
+ n1 >= d1 (true due to program flow). */
+ if (n1 > d1 || n0 >= d0)
+ {
+ q0 = 1;
+ sub_ddmmss (n1, n0, n1, n0, d1, d0);
+ }
+ else
+ q0 = 0;
+
+ q1 = 0;
+
+ r0 = n0;
+ r1 = n1;
+ }
+ else
+ {
+ _FP_W_TYPE m1, m0, n2;
+
+ /* Normalize. */
+
+ b = _FP_W_TYPE_SIZE - bm;
+
+ d1 = (d1 << bm) | (d0 >> b);
+ d0 = d0 << bm;
+ n2 = n1 >> b;
+ n1 = (n1 << bm) | (n0 >> b);
+ n0 = n0 << bm;
+
+ udiv_qrnnd (q0, n1, n2, n1, d1);
+ umul_ppmm (m1, m0, q0, d0);
+
+ if (m1 > n1 || (m1 == n1 && m0 > n0))
+ {
+ q0--;
+ sub_ddmmss (m1, m0, m1, m0, d1, d0);
+ }
+
+ q1 = 0;
+
+ /* Remainder in (n1n0 - m1m0) >> bm. */
+ sub_ddmmss (n1, n0, n1, n0, m1, m0);
+ r0 = (n1 << b) | (n0 >> bm);
+ r1 = n1 >> bm;
+ }
+ }
+ }
+
+ q[0] = q0; q[1] = q1;
+ r[0] = r0, r[1] = r1;
+}