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Diffstat (limited to 'modules/asm/mp_amd64/mp_mulop.cpp')
-rw-r--r-- | modules/asm/mp_amd64/mp_mulop.cpp | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/modules/asm/mp_amd64/mp_mulop.cpp b/modules/asm/mp_amd64/mp_mulop.cpp new file mode 100644 index 000000000..d1aa51489 --- /dev/null +++ b/modules/asm/mp_amd64/mp_mulop.cpp @@ -0,0 +1,94 @@ +/************************************************* +* Simple O(N^2) Multiplication and Squaring * +* (C) 1999-2008 Jack Lloyd * +*************************************************/ + +#include <botan/mp_asm.h> +#include <botan/mp_asmi.h> +#include <botan/mp_core.h> +#include <botan/mem_ops.h> + +namespace Botan { + +extern "C" { + +/************************************************* +* Simple O(N^2) Multiplication * +*************************************************/ +void bigint_simple_mul(word z[], const word x[], u32bit x_size, + const word y[], u32bit y_size) + { + const u32bit blocks = x_size - (x_size % 8); + + clear_mem(z, x_size + y_size); + + for(u32bit i = 0; i != y_size; ++i) + { + word carry = 0; + + for(u32bit j = 0; j != blocks; j += 8) + carry = word8_madd3(z + i + j, x + j, y[i], carry); + + for(u32bit j = blocks; j != x_size; ++j) + z[i+j] = word_madd3(x[j], y[i], z[i+j], &carry); + + z[x_size+i] = carry; + } + } + +inline word word_sqr(word x, + +/************************************************* +* Simple O(N^2) Squaring + +This is exactly the same algorithm as bigint_simple_mul, +however because C/C++ compilers suck at alias analysis it +is good to have the version where the compiler knows +that x == y +*************************************************/ +void bigint_simple_sqr(word z[], const word x[], u32bit x_size) + { + clear_mem(z, 2*x_size); + + for(u32bit i = 0; i != x_size; ++i) + { + const word x_i = x[i]; + + word carry = z[2*i]; + z[2*i] = word_madd2(x_i, x_i, z[2*i], &carry); + + for(u32bit j = i; j != x_size; ++j) + { + // z[i+j] = z[i+j] + 2 * x[j] * x_i + carry; + + /* + load z[i+j] into register + load x[j] into %hi + mulq %[x_i] -> x[i] * x[j] -> %lo:%hi + shlq %lo, $1 + + // put carry bit (cf) from %lo into %temp + xorl %temp + adcq $0, %temp + + // high bit of lo now in cf + shl %hi, $1 + // add in lowest bid from %lo + orl %temp, %hi + + addq %[c], %[lo] + adcq $0, %[hi] + addq %[z_ij], %[lo] + adcq $0, %[hi] + + */ + + } + + z[x_size+i] = carry; + } + } + +} + +} |