From f1fcd76ba7514003135f3d76ef2308b86b754507 Mon Sep 17 00:00:00 2001
From: Jeff Garzik <jeff@garzik.org>
Date: Mon, 6 Dec 2010 20:14:58 -0500
Subject: [PATCH] sha256_cryptopp: Add crypto++ 32-bit assembly implementation

---
 cpu-miner.c       |  19 +-
 miner.h           |   7 +
 sha256_cryptopp.c | 494 +++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 518 insertions(+), 2 deletions(-)

diff --git a/cpu-miner.c b/cpu-miner.c
index 70974c32..db1fd575 100644
--- a/cpu-miner.c
+++ b/cpu-miner.c
@@ -39,7 +39,8 @@ enum sha256_algos {
 	ALGO_C,			/* plain C */
 	ALGO_4WAY,		/* parallel SSE2 */
 	ALGO_VIA,		/* VIA padlock */
-	ALGO_CRYPTOPP,		/* Crypto++ */
+	ALGO_CRYPTOPP,		/* Crypto++ (C) */
+	ALGO_CRYPTOPP_ASM32,	/* Crypto++ 32-bit assembly */
 };
 
 static const char *algo_names[] = {
@@ -51,6 +52,9 @@ static const char *algo_names[] = {
 	[ALGO_VIA]		= "via",
 #endif
 	[ALGO_CRYPTOPP]		= "cryptopp",
+#ifdef WANT_CRYPTOPP_ASM32
+	[ALGO_CRYPTOPP_ASM32]	= "cryptopp_asm32",
+#endif
 };
 
 bool opt_debug = false;
@@ -82,6 +86,9 @@ static struct option_help options_help[] = {
 	  "\n\tvia\t\tVIA padlock implementation"
 #endif
 	  "\n\tcryptopp\tCrypto++ library implementation (EXPERIMENTAL)"
+#ifdef WANT_CRYPTOPP_ASM32
+	  "\n\tcryptopp_asm32\tCrypto++ library implementation (EXPERIMENTAL)"
+#endif
 	  },
 
 	{ "debug",
@@ -294,6 +301,16 @@ static void *miner_thread(void *thr_id_int)
 				        work.hash1, work.hash, &hashes_done);
 			break;
 
+#ifdef WANT_CRYPTOPP_ASM32
+		case ALGO_CRYPTOPP_ASM32:
+			rc = scanhash_asm32(work.midstate, work.data + 64,
+				        work.hash1, work.hash, &hashes_done);
+			break;
+#endif
+
+		default:
+			/* should never happen */
+			return NULL;
 		}
 
 		hashmeter(thr_id, &tv_start, hashes_done);
diff --git a/miner.h b/miner.h
index 09157fa6..b77bf0d4 100644
--- a/miner.h
+++ b/miner.h
@@ -14,6 +14,10 @@
 #define WANT_VIA_PADLOCK 1
 #endif
 
+#if defined(__i386__)
+#define WANT_CRYPTOPP_ASM32
+#endif
+
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 #endif
@@ -40,6 +44,9 @@ extern bool scanhash_c(const unsigned char *midstate, unsigned char *data,
 extern bool scanhash_cryptopp(const unsigned char *midstate,unsigned char *data,
 	      unsigned char *hash1, unsigned char *hash,
 	      unsigned long *hashes_done);
+extern bool scanhash_asm32(const unsigned char *midstate,unsigned char *data,
+	      unsigned char *hash1, unsigned char *hash,
+	      unsigned long *hashes_done);
 
 extern int
 timeval_subtract (struct timeval *result, struct timeval *x, struct timeval *y);
diff --git a/sha256_cryptopp.c b/sha256_cryptopp.c
index 40772f41..3c200434 100644
--- a/sha256_cryptopp.c
+++ b/sha256_cryptopp.c
@@ -59,7 +59,7 @@ static const word32 SHA256_K[64] = {
 
 static void SHA256_Transform(word32 *state, const word32 *data)
 {
-	word32 W[16];
+	word32 W[16] = { };
 	word32 T[8];
 	unsigned int j;
 
@@ -131,3 +131,495 @@ bool scanhash_cryptopp(const unsigned char *midstate, unsigned char *data,
 	}
 }
 
+#if defined(WANT_CRYPTOPP_ASM32)
+
+#define CRYPTOPP_FASTCALL
+#define CRYPTOPP_BOOL_X86 1
+#define CRYPTOPP_BOOL_X64 0
+#define CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE 0
+
+#ifdef CRYPTOPP_GENERATE_X64_MASM
+	#define AS1(x) x*newline*
+	#define AS2(x, y) x, y*newline*
+	#define AS3(x, y, z) x, y, z*newline*
+	#define ASS(x, y, a, b, c, d) x, y, a*64+b*16+c*4+d*newline*
+	#define ASL(x) label##x:*newline*
+	#define ASJ(x, y, z) x label##y*newline*
+	#define ASC(x, y) x label##y*newline*
+	#define AS_HEX(y) 0##y##h
+#elif defined(_MSC_VER) || defined(__BORLANDC__)
+	#define CRYPTOPP_MS_STYLE_INLINE_ASSEMBLY
+	#define AS1(x) __asm {x}
+	#define AS2(x, y) __asm {x, y}
+	#define AS3(x, y, z) __asm {x, y, z}
+	#define ASS(x, y, a, b, c, d) __asm {x, y, (a)*64+(b)*16+(c)*4+(d)}
+	#define ASL(x) __asm {label##x:}
+	#define ASJ(x, y, z) __asm {x label##y}
+	#define ASC(x, y) __asm {x label##y}
+	#define CRYPTOPP_NAKED __declspec(naked)
+	#define AS_HEX(y) 0x##y
+#else
+	#define CRYPTOPP_GNU_STYLE_INLINE_ASSEMBLY
+	// define these in two steps to allow arguments to be expanded
+	#define GNU_AS1(x) #x ";"
+	#define GNU_AS2(x, y) #x ", " #y ";"
+	#define GNU_AS3(x, y, z) #x ", " #y ", " #z ";"
+	#define GNU_ASL(x) "\n" #x ":"
+	#define GNU_ASJ(x, y, z) #x " " #y #z ";"
+	#define AS1(x) GNU_AS1(x)
+	#define AS2(x, y) GNU_AS2(x, y)
+	#define AS3(x, y, z) GNU_AS3(x, y, z)
+	#define ASS(x, y, a, b, c, d) #x ", " #y ", " #a "*64+" #b "*16+" #c "*4+" #d ";"
+	#define ASL(x) GNU_ASL(x)
+	#define ASJ(x, y, z) GNU_ASJ(x, y, z)
+	#define ASC(x, y) #x " " #y ";"
+	#define CRYPTOPP_NAKED
+	#define AS_HEX(y) 0x##y
+#endif
+
+#define IF0(y)
+#define IF1(y) y
+
+#ifdef CRYPTOPP_GENERATE_X64_MASM
+#define ASM_MOD(x, y) ((x) MOD (y))
+#define XMMWORD_PTR XMMWORD PTR
+#else
+// GNU assembler doesn't seem to have mod operator
+#define ASM_MOD(x, y) ((x)-((x)/(y))*(y))
+// GAS 2.15 doesn't support XMMWORD PTR. it seems necessary only for MASM
+#define XMMWORD_PTR
+#endif
+
+#if CRYPTOPP_BOOL_X86
+	#define AS_REG_1 ecx
+	#define AS_REG_2 edx
+	#define AS_REG_3 esi
+	#define AS_REG_4 edi
+	#define AS_REG_5 eax
+	#define AS_REG_6 ebx
+	#define AS_REG_7 ebp
+	#define AS_REG_1d ecx
+	#define AS_REG_2d edx
+	#define AS_REG_3d esi
+	#define AS_REG_4d edi
+	#define AS_REG_5d eax
+	#define AS_REG_6d ebx
+	#define AS_REG_7d ebp
+	#define WORD_SZ 4
+	#define WORD_REG(x)	e##x
+	#define WORD_PTR DWORD PTR
+	#define AS_PUSH_IF86(x) AS1(push e##x)
+	#define AS_POP_IF86(x) AS1(pop e##x)
+	#define AS_JCXZ jecxz
+#elif CRYPTOPP_BOOL_X64
+	#ifdef CRYPTOPP_GENERATE_X64_MASM
+		#define AS_REG_1 rcx
+		#define AS_REG_2 rdx
+		#define AS_REG_3 r8
+		#define AS_REG_4 r9
+		#define AS_REG_5 rax
+		#define AS_REG_6 r10
+		#define AS_REG_7 r11
+		#define AS_REG_1d ecx
+		#define AS_REG_2d edx
+		#define AS_REG_3d r8d
+		#define AS_REG_4d r9d
+		#define AS_REG_5d eax
+		#define AS_REG_6d r10d
+		#define AS_REG_7d r11d
+	#else
+		#define AS_REG_1 rdi
+		#define AS_REG_2 rsi
+		#define AS_REG_3 rdx
+		#define AS_REG_4 rcx
+		#define AS_REG_5 r8
+		#define AS_REG_6 r9
+		#define AS_REG_7 r10
+		#define AS_REG_1d edi
+		#define AS_REG_2d esi
+		#define AS_REG_3d edx
+		#define AS_REG_4d ecx
+		#define AS_REG_5d r8d
+		#define AS_REG_6d r9d
+		#define AS_REG_7d r10d
+	#endif
+	#define WORD_SZ 8
+	#define WORD_REG(x)	r##x
+	#define WORD_PTR QWORD PTR
+	#define AS_PUSH_IF86(x)
+	#define AS_POP_IF86(x)
+	#define AS_JCXZ jrcxz
+#endif
+
+static void CRYPTOPP_FASTCALL X86_SHA256_HashBlocks(word32 *state, const word32 *data, size_t len
+#if defined(_MSC_VER) && (_MSC_VER == 1200)
+	, ...	// VC60 workaround: prevent VC 6 from inlining this function
+#endif
+	)
+{
+#if defined(_MSC_VER) && (_MSC_VER == 1200)
+	AS2(mov ecx, [state])
+	AS2(mov edx, [data])
+#endif
+
+	#define LOCALS_SIZE	8*4 + 16*4 + 4*WORD_SZ
+	#define H(i)		[BASE+ASM_MOD(1024+7-(i),8)*4]
+	#define G(i)		H(i+1)
+	#define F(i)		H(i+2)
+	#define E(i)		H(i+3)
+	#define D(i)		H(i+4)
+	#define C(i)		H(i+5)
+	#define B(i)		H(i+6)
+	#define A(i)		H(i+7)
+	#define Wt(i)		BASE+8*4+ASM_MOD(1024+15-(i),16)*4
+	#define Wt_2(i)		Wt((i)-2)
+	#define Wt_15(i)	Wt((i)-15)
+	#define Wt_7(i)		Wt((i)-7)
+	#define K_END		[BASE+8*4+16*4+0*WORD_SZ]
+	#define STATE_SAVE	[BASE+8*4+16*4+1*WORD_SZ]
+	#define DATA_SAVE	[BASE+8*4+16*4+2*WORD_SZ]
+	#define DATA_END	[BASE+8*4+16*4+3*WORD_SZ]
+	#define Kt(i)		WORD_REG(si)+(i)*4
+#if CRYPTOPP_BOOL_X86
+	#define BASE		esp+4
+#elif defined(__GNUC__)
+	#define BASE		r8
+#else
+	#define BASE		rsp
+#endif
+
+#define RA0(i, edx, edi)		\
+	AS2(	add edx, [Kt(i)]	)\
+	AS2(	add edx, [Wt(i)]	)\
+	AS2(	add edx, H(i)		)\
+
+#define RA1(i, edx, edi)
+
+#define RB0(i, edx, edi)
+
+#define RB1(i, edx, edi)	\
+	AS2(	mov AS_REG_7d, [Wt_2(i)]	)\
+	AS2(	mov edi, [Wt_15(i)])\
+	AS2(	mov ebx, AS_REG_7d	)\
+	AS2(	shr AS_REG_7d, 10		)\
+	AS2(	ror ebx, 17		)\
+	AS2(	xor AS_REG_7d, ebx	)\
+	AS2(	ror ebx, 2		)\
+	AS2(	xor ebx, AS_REG_7d	)/* s1(W_t-2) */\
+	AS2(	add ebx, [Wt_7(i)])\
+	AS2(	mov AS_REG_7d, edi	)\
+	AS2(	shr AS_REG_7d, 3		)\
+	AS2(	ror edi, 7		)\
+	AS2(	add ebx, [Wt(i)])/* s1(W_t-2) + W_t-7 + W_t-16 */\
+	AS2(	xor AS_REG_7d, edi	)\
+	AS2(	add edx, [Kt(i)])\
+	AS2(	ror edi, 11		)\
+	AS2(	add edx, H(i)	)\
+	AS2(	xor AS_REG_7d, edi	)/* s0(W_t-15) */\
+	AS2(	add AS_REG_7d, ebx	)/* W_t = s1(W_t-2) + W_t-7 + s0(W_t-15) W_t-16*/\
+	AS2(	mov [Wt(i)], AS_REG_7d)\
+	AS2(	add edx, AS_REG_7d	)\
+
+#define ROUND(i, r, eax, ecx, edi, edx)\
+	/* in: edi = E	*/\
+	/* unused: eax, ecx, temp: ebx, AS_REG_7d, out: edx = T1 */\
+	AS2(	mov edx, F(i)	)\
+	AS2(	xor edx, G(i)	)\
+	AS2(	and edx, edi	)\
+	AS2(	xor edx, G(i)	)/* Ch(E,F,G) = (G^(E&(F^G))) */\
+	AS2(	mov AS_REG_7d, edi	)\
+	AS2(	ror edi, 6		)\
+	AS2(	ror AS_REG_7d, 25		)\
+	RA##r(i, edx, edi		)/* H + Wt + Kt + Ch(E,F,G) */\
+	AS2(	xor AS_REG_7d, edi	)\
+	AS2(	ror edi, 5		)\
+	AS2(	xor AS_REG_7d, edi	)/* S1(E) */\
+	AS2(	add edx, AS_REG_7d	)/* T1 = S1(E) + Ch(E,F,G) + H + Wt + Kt */\
+	RB##r(i, edx, edi		)/* H + Wt + Kt + Ch(E,F,G) */\
+	/* in: ecx = A, eax = B^C, edx = T1 */\
+	/* unused: edx, temp: ebx, AS_REG_7d, out: eax = A, ecx = B^C, edx = E */\
+	AS2(	mov ebx, ecx	)\
+	AS2(	xor ecx, B(i)	)/* A^B */\
+	AS2(	and eax, ecx	)\
+	AS2(	xor eax, B(i)	)/* Maj(A,B,C) = B^((A^B)&(B^C) */\
+	AS2(	mov AS_REG_7d, ebx	)\
+	AS2(	ror ebx, 2		)\
+	AS2(	add eax, edx	)/* T1 + Maj(A,B,C) */\
+	AS2(	add edx, D(i)	)\
+	AS2(	mov D(i), edx	)\
+	AS2(	ror AS_REG_7d, 22		)\
+	AS2(	xor AS_REG_7d, ebx	)\
+	AS2(	ror ebx, 11		)\
+	AS2(	xor AS_REG_7d, ebx	)\
+	AS2(	add eax, AS_REG_7d	)/* T1 + S0(A) + Maj(A,B,C) */\
+	AS2(	mov H(i), eax	)\
+
+#define SWAP_COPY(i)		\
+	AS2(	mov		WORD_REG(bx), [WORD_REG(dx)+i*WORD_SZ])\
+	AS1(	bswap	WORD_REG(bx))\
+	AS2(	mov		[Wt(i*(1+CRYPTOPP_BOOL_X64)+CRYPTOPP_BOOL_X64)], WORD_REG(bx))
+
+#if defined(__GNUC__)
+	#if CRYPTOPP_BOOL_X64
+		FixedSizeAlignedSecBlock<byte, LOCALS_SIZE> workspace;
+	#endif
+	__asm__ __volatile__
+	(
+	#if CRYPTOPP_BOOL_X64
+		"lea %4, %%r8;"
+	#endif
+	".intel_syntax noprefix;"
+#elif defined(CRYPTOPP_GENERATE_X64_MASM)
+		ALIGN   8
+	X86_SHA256_HashBlocks	PROC FRAME
+		rex_push_reg rsi
+		push_reg rdi
+		push_reg rbx
+		push_reg rbp
+		alloc_stack(LOCALS_SIZE+8)
+		.endprolog
+		mov rdi, r8
+		lea rsi, [?SHA256_K@CryptoPP@@3QBIB + 48*4]
+#endif
+
+#if CRYPTOPP_BOOL_X86
+	#ifndef __GNUC__
+		AS2(	mov		edi, [len])
+		AS2(	lea		WORD_REG(si), [SHA256_K+48*4])
+	#endif
+	#if !defined(_MSC_VER) || (_MSC_VER < 1400)
+		AS_PUSH_IF86(bx)
+	#endif
+
+	AS_PUSH_IF86(bp)
+	AS2(	mov		ebx, esp)
+	AS2(	and		esp, -16)
+	AS2(	sub		WORD_REG(sp), LOCALS_SIZE)
+	AS_PUSH_IF86(bx)
+#endif
+	AS2(	mov		STATE_SAVE, WORD_REG(cx))
+	AS2(	mov		DATA_SAVE, WORD_REG(dx))
+	AS2(	lea		WORD_REG(ax), [WORD_REG(di) + WORD_REG(dx)])
+	AS2(	mov		DATA_END, WORD_REG(ax))
+	AS2(	mov		K_END, WORD_REG(si))
+
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+#if CRYPTOPP_BOOL_X86
+	AS2(	test	edi, 1)
+	ASJ(	jnz,	2, f)
+	AS1(	dec		DWORD PTR K_END)
+#endif
+	AS2(	movdqa	xmm0, XMMWORD_PTR [WORD_REG(cx)+0*16])
+	AS2(	movdqa	xmm1, XMMWORD_PTR [WORD_REG(cx)+1*16])
+#endif
+
+#if CRYPTOPP_BOOL_X86
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+	ASJ(	jmp,	0, f)
+#endif
+	ASL(2)	// non-SSE2
+	AS2(	mov		esi, ecx)
+	AS2(	lea		edi, A(0))
+	AS2(	mov		ecx, 8)
+	AS1(	rep movsd)
+	AS2(	mov		esi, K_END)
+	ASJ(	jmp,	3, f)
+#endif
+
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+	ASL(0)
+	AS2(	movdqa	E(0), xmm1)
+	AS2(	movdqa	A(0), xmm0)
+#endif
+#if CRYPTOPP_BOOL_X86
+	ASL(3)
+#endif
+	AS2(	sub		WORD_REG(si), 48*4)
+	SWAP_COPY(0)	SWAP_COPY(1)	SWAP_COPY(2)	SWAP_COPY(3)
+	SWAP_COPY(4)	SWAP_COPY(5)	SWAP_COPY(6)	SWAP_COPY(7)
+#if CRYPTOPP_BOOL_X86
+	SWAP_COPY(8)	SWAP_COPY(9)	SWAP_COPY(10)	SWAP_COPY(11)
+	SWAP_COPY(12)	SWAP_COPY(13)	SWAP_COPY(14)	SWAP_COPY(15)
+#endif
+	AS2(	mov		edi, E(0))	// E
+	AS2(	mov		eax, B(0))	// B
+	AS2(	xor		eax, C(0))	// B^C
+	AS2(	mov		ecx, A(0))	// A
+
+	ROUND(0, 0, eax, ecx, edi, edx)
+	ROUND(1, 0, ecx, eax, edx, edi)
+	ROUND(2, 0, eax, ecx, edi, edx)
+	ROUND(3, 0, ecx, eax, edx, edi)
+	ROUND(4, 0, eax, ecx, edi, edx)
+	ROUND(5, 0, ecx, eax, edx, edi)
+	ROUND(6, 0, eax, ecx, edi, edx)
+	ROUND(7, 0, ecx, eax, edx, edi)
+	ROUND(8, 0, eax, ecx, edi, edx)
+	ROUND(9, 0, ecx, eax, edx, edi)
+	ROUND(10, 0, eax, ecx, edi, edx)
+	ROUND(11, 0, ecx, eax, edx, edi)
+	ROUND(12, 0, eax, ecx, edi, edx)
+	ROUND(13, 0, ecx, eax, edx, edi)
+	ROUND(14, 0, eax, ecx, edi, edx)
+	ROUND(15, 0, ecx, eax, edx, edi)
+
+	ASL(1)
+	AS2(add WORD_REG(si), 4*16)
+	ROUND(0, 1, eax, ecx, edi, edx)
+	ROUND(1, 1, ecx, eax, edx, edi)
+	ROUND(2, 1, eax, ecx, edi, edx)
+	ROUND(3, 1, ecx, eax, edx, edi)
+	ROUND(4, 1, eax, ecx, edi, edx)
+	ROUND(5, 1, ecx, eax, edx, edi)
+	ROUND(6, 1, eax, ecx, edi, edx)
+	ROUND(7, 1, ecx, eax, edx, edi)
+	ROUND(8, 1, eax, ecx, edi, edx)
+	ROUND(9, 1, ecx, eax, edx, edi)
+	ROUND(10, 1, eax, ecx, edi, edx)
+	ROUND(11, 1, ecx, eax, edx, edi)
+	ROUND(12, 1, eax, ecx, edi, edx)
+	ROUND(13, 1, ecx, eax, edx, edi)
+	ROUND(14, 1, eax, ecx, edi, edx)
+	ROUND(15, 1, ecx, eax, edx, edi)
+	AS2(	cmp		WORD_REG(si), K_END)
+	ASJ(	jb,		1, b)
+
+	AS2(	mov		WORD_REG(dx), DATA_SAVE)
+	AS2(	add		WORD_REG(dx), 64)
+	AS2(	mov		AS_REG_7, STATE_SAVE)
+	AS2(	mov		DATA_SAVE, WORD_REG(dx))
+
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+#if CRYPTOPP_BOOL_X86
+	AS2(	test	DWORD PTR K_END, 1)
+	ASJ(	jz,		4, f)
+#endif
+	AS2(	movdqa	xmm1, XMMWORD_PTR [AS_REG_7+1*16])
+	AS2(	movdqa	xmm0, XMMWORD_PTR [AS_REG_7+0*16])
+	AS2(	paddd	xmm1, E(0))
+	AS2(	paddd	xmm0, A(0))
+	AS2(	movdqa	[AS_REG_7+1*16], xmm1)
+	AS2(	movdqa	[AS_REG_7+0*16], xmm0)
+	AS2(	cmp		WORD_REG(dx), DATA_END)
+	ASJ(	jb,		0, b)
+#endif
+
+#if CRYPTOPP_BOOL_X86
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+	ASJ(	jmp,	5, f)
+	ASL(4)	// non-SSE2
+#endif
+	AS2(	add		[AS_REG_7+0*4], ecx)	// A
+	AS2(	add		[AS_REG_7+4*4], edi)	// E
+	AS2(	mov		eax, B(0))
+	AS2(	mov		ebx, C(0))
+	AS2(	mov		ecx, D(0))
+	AS2(	add		[AS_REG_7+1*4], eax)
+	AS2(	add		[AS_REG_7+2*4], ebx)
+	AS2(	add		[AS_REG_7+3*4], ecx)
+	AS2(	mov		eax, F(0))
+	AS2(	mov		ebx, G(0))
+	AS2(	mov		ecx, H(0))
+	AS2(	add		[AS_REG_7+5*4], eax)
+	AS2(	add		[AS_REG_7+6*4], ebx)
+	AS2(	add		[AS_REG_7+7*4], ecx)
+	AS2(	mov		ecx, AS_REG_7d)
+	AS2(	cmp		WORD_REG(dx), DATA_END)
+	ASJ(	jb,		2, b)
+#if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE
+	ASL(5)
+#endif
+#endif
+
+	AS_POP_IF86(sp)
+	AS_POP_IF86(bp)
+	#if !defined(_MSC_VER) || (_MSC_VER < 1400)
+		AS_POP_IF86(bx)
+	#endif
+
+#ifdef CRYPTOPP_GENERATE_X64_MASM
+	add		rsp, LOCALS_SIZE+8
+	pop		rbp
+	pop		rbx
+	pop		rdi
+	pop		rsi
+	ret
+	X86_SHA256_HashBlocks ENDP
+#endif
+
+#ifdef __GNUC__
+	".att_syntax prefix;"
+	: 
+	: "c" (state), "d" (data), "S" (SHA256_K+48), "D" (len)
+	#if CRYPTOPP_BOOL_X64
+		, "m" (workspace[0])
+	#endif
+	: "memory", "cc", "%eax"
+	#if CRYPTOPP_BOOL_X64
+		, "%rbx", "%r8", "%r10"
+	#endif
+	);
+#endif
+}
+
+static inline bool HasSSE2(void) { return false; }
+
+static void SHA256_Transform32(word32 *state, const word32 *data)
+{
+	word32 W[16];
+	int i;
+
+	for (i = 0; i < 16; i++)
+		W[i] = ((word32 *)(data))[i];
+
+	X86_SHA256_HashBlocks(state, W, 16 * 4);
+}
+
+static void runhash32(void *state, const void *input, const void *init)
+{
+	memcpy(state, init, 32);
+	SHA256_Transform32(state, input);
+}
+
+/* suspiciously similar to ScanHash* from bitcoin */
+bool scanhash_asm32(const unsigned char *midstate, unsigned char *data,
+	        unsigned char *hash1, unsigned char *hash,
+	        unsigned long *hashes_done)
+{
+	uint32_t *hash32 = (uint32_t *) hash;
+	uint32_t *nonce = (uint32_t *)(data + 12);
+	uint32_t n = 0;
+	unsigned long stat_ctr = 0;
+
+	while (1) {
+		n++;
+		*nonce = n;
+
+		runhash32(hash1, data, midstate);
+		runhash32(hash, hash1, sha256_init_state);
+
+		stat_ctr++;
+
+		if (hash32[7] == 0) {
+			char *hexstr;
+
+			hexstr = bin2hex(hash, 32);
+			fprintf(stderr,
+				"DBG: found zeroes in hash:\n%s\n",
+				hexstr);
+			free(hexstr);
+
+			*hashes_done = stat_ctr;
+			return true;
+		}
+
+		if ((n & 0xffffff) == 0) {
+			if (opt_debug)
+				fprintf(stderr, "DBG: end of nonce range\n");
+			*hashes_done = stat_ctr;
+			return false;
+		}
+	}
+}
+
+#endif	// #if defined(WANT_CRYPTOPP_ASM32)