Merge pull request #19183 from karalabe/bn256-arm64-go1.12-fix

crypto/bn256/cloudflare: pull in upstream fix for Go 1.12 R18

crypto/bn256/cloudflare/mul_arm64.h

@@ -12,7 +12,7 @@
 	UMULH R1, R8, c4 \
 	ADCS ZR, c4 \
 	\
-	MUL R2, R5, R25 \
+	MUL R2, R5, R1 \
 	UMULH R2, R5, R26 \
 	MUL R2, R6, R0 \
 	ADDS R0, R26 \
@@ -24,13 +24,13 @@
 	ADCS R0, R29 \
 	UMULH R2, R8, c5 \
 	ADCS ZR, c5 \
-	ADDS R25, c1 \
+	ADDS R1, c1 \
 	ADCS R26, c2 \
 	ADCS R27, c3 \
 	ADCS R29, c4 \
 	ADCS  ZR, c5 \
 	\
-	MUL R3, R5, R25 \
+	MUL R3, R5, R1 \
 	UMULH R3, R5, R26 \
 	MUL R3, R6, R0 \
 	ADDS R0, R26 \
@@ -42,13 +42,13 @@
 	ADCS R0, R29 \
 	UMULH R3, R8, c6 \
 	ADCS ZR, c6 \
-	ADDS R25, c2 \
+	ADDS R1, c2 \
 	ADCS R26, c3 \
 	ADCS R27, c4 \
 	ADCS R29, c5 \
 	ADCS  ZR, c6 \
 	\
-	MUL R4, R5, R25 \
+	MUL R4, R5, R1 \
 	UMULH R4, R5, R26 \
 	MUL R4, R6, R0 \
 	ADDS R0, R26 \
@@ -60,7 +60,7 @@
 	ADCS R0, R29 \
 	UMULH R4, R8, c7 \
 	ADCS ZR, c7 \
-	ADDS R25, c3 \
+	ADDS R1, c3 \
 	ADCS R26, c4 \
 	ADCS R27, c5 \
 	ADCS R29, c6 \
@@ -69,15 +69,15 @@
 #define gfpReduce() \
 	\ // m = (T * N') mod R, store m in R1:R2:R3:R4
 	MOVD ·np+0(SB), R17 \
-	MOVD ·np+8(SB), R18 \
+	MOVD ·np+8(SB), R25 \
 	MOVD ·np+16(SB), R19 \
 	MOVD ·np+24(SB), R20 \
 	\
 	MUL R9, R17, R1 \
 	UMULH R9, R17, R2 \
-	MUL R9, R18, R0 \
+	MUL R9, R25, R0 \
 	ADDS R0, R2 \
-	UMULH R9, R18, R3 \
+	UMULH R9, R25, R3 \
 	MUL R9, R19, R0 \
 	ADCS R0, R3 \
 	UMULH R9, R19, R4 \
@@ -86,9 +86,9 @@
 	\
 	MUL R10, R17, R21 \
 	UMULH R10, R17, R22 \
-	MUL R10, R18, R0 \
+	MUL R10, R25, R0 \
 	ADDS R0, R22 \
-	UMULH R10, R18, R23 \
+	UMULH R10, R25, R23 \
 	MUL R10, R19, R0 \
 	ADCS R0, R23 \
 	ADDS R21, R2 \
@@ -97,7 +97,7 @@
 	\
 	MUL R11, R17, R21 \
 	UMULH R11, R17, R22 \
-	MUL R11, R18, R0 \
+	MUL R11, R25, R0 \
 	ADDS R0, R22 \
 	ADDS R21, R3 \
 	ADCS R22, R4 \
@@ -107,19 +107,19 @@
 	\
 	\ // m * N
 	loadModulus(R5,R6,R7,R8) \
-	mul(R17,R18,R19,R20,R21,R22,R23,R24) \
+	mul(R17,R25,R19,R20,R21,R22,R23,R24) \
 	\
 	\ // Add the 512-bit intermediate to m*N
-	MOVD  ZR, R25 \
+	MOVD  ZR, R0 \
 	ADDS  R9, R17 \
-	ADCS R10, R18 \
+	ADCS R10, R25 \
 	ADCS R11, R19 \
 	ADCS R12, R20 \
 	ADCS R13, R21 \
 	ADCS R14, R22 \
 	ADCS R15, R23 \
 	ADCS R16, R24 \
-	ADCS  ZR, R25 \
+	ADCS  ZR, R0 \
 	\
 	\ // Our output is R21:R22:R23:R24. Reduce mod p if necessary.
 	SUBS R5, R21, R10 \