Fix "error: impossible constraint in asm" under Aarch64 (Issue 366)

1 files changed, 20 insertions, 3 deletions

diff --git a/gcm.cpp b/gcm.cpp
index 4e3e2845..8602fbc8 100644
--- a/gcm.cpp
+++ b/gcm.cpp
@@ -90,6 +90,16 @@ inline uint64x2_t VEXT_8(uint64x2_t a, uint64x2_t b, unsigned int c)
         :"=w" (r) : "w" (a), "w" (b), "I" (c) );

 	return r;

 }

+

+// https://github.com/weidai11/cryptopp/issues/366

+template <unsigned int C>

+inline uint64x2_t VEXT_8(uint64x2_t a, uint64x2_t b)

+{

+	uint64x2_t r;

+    __asm __volatile("ext   %0.16b, %1.16b, %2.16b, %3 \n\t"

+        :"=w" (r) : "w" (a), "w" (b), "I" (C) );

+	return r;

+}

 #endif // GCC and compatibles

 

 #if defined(_MSC_VER)

@@ -121,6 +131,13 @@ inline uint64x2_t VEXT_8(uint64x2_t a, uint64x2_t b, unsigned int c)
 {

 	return (uint64x2_t)vextq_u8(vreinterpretq_u8_u64(a), vreinterpretq_u8_u64(b), c);

 }

+

+// https://github.com/weidai11/cryptopp/issues/366

+template <unsigned int C>

+inline uint64x2_t VEXT_8(uint64x2_t a, uint64x2_t b)

+{

+	return (uint64x2_t)vextq_u8(vreinterpretq_u8_u64(a), vreinterpretq_u8_u64(b), C);

+}

 #endif // Microsoft and compatibles

 #endif // CRYPTOPP_BOOL_ARM_PMULL_AVAILABLE

 

@@ -276,13 +293,13 @@ static const unsigned int s_clmulTableSizeInBlocks = 8;
 inline uint64x2_t PMULL_Reduce(uint64x2_t c0, uint64x2_t c1, uint64x2_t c2, const uint64x2_t &r)

 {

 	// See comments fo CLMUL_Reduce

-	c1 = veorq_u64(c1, VEXT_8(vdupq_n_u64(0), c0, 8));

+	c1 = veorq_u64(c1, VEXT_8<8>(vdupq_n_u64(0), c0));

 	c1 = veorq_u64(c1, PMULL_01(c0, r));

-	c0 = VEXT_8(c0, vdupq_n_u64(0), 8);

+	c0 = VEXT_8<8>(c0, vdupq_n_u64(0));

 	c0 = vshlq_n_u64(veorq_u64(c0, c1), 1);

 	c0 = PMULL_00(c0, r);

 	c2 = veorq_u64(c2, c0);

-	c2 = veorq_u64(c2, VEXT_8(c1, vdupq_n_u64(0), 8));

+	c2 = veorq_u64(c2, VEXT_8<8>(c1, vdupq_n_u64(0)));

 	c1 = vshrq_n_u64(vcombine_u64(vget_low_u64(c1), vget_low_u64(c2)), 63);

 	c2 = vshlq_n_u64(c2, 1);