curve25519: avoid loss of R15 in -dynlink mode
Fixes golang/go#18820.
Change-Id: I4b3a49b3bbbecc4e1008989fefd39da9725a28ea
Reviewed-on: https://go-review.googlesource.com/36359
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Adam Langley <agl@golang.org>
diff --git a/curve25519/const_amd64.h b/curve25519/const_amd64.h
new file mode 100644
index 0000000..80ad222
--- /dev/null
+++ b/curve25519/const_amd64.h
@@ -0,0 +1,8 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+
+#define REDMASK51 0x0007FFFFFFFFFFFF
diff --git a/curve25519/const_amd64.s b/curve25519/const_amd64.s
index 797f9b0..0ad5398 100644
--- a/curve25519/const_amd64.s
+++ b/curve25519/const_amd64.s
@@ -7,8 +7,8 @@
// +build amd64,!gccgo,!appengine
-DATA ·REDMASK51(SB)/8, $0x0007FFFFFFFFFFFF
-GLOBL ·REDMASK51(SB), 8, $8
+// These constants cannot be encoded in non-MOVQ immediates.
+// We access them directly from memory instead.
DATA ·_121666_213(SB)/8, $996687872
GLOBL ·_121666_213(SB), 8, $8
diff --git a/curve25519/freeze_amd64.s b/curve25519/freeze_amd64.s
index 932800b..536479b 100644
--- a/curve25519/freeze_amd64.s
+++ b/curve25519/freeze_amd64.s
@@ -7,6 +7,8 @@
// +build amd64,!gccgo,!appengine
+#include "const_amd64.h"
+
// func freeze(inout *[5]uint64)
TEXT ·freeze(SB),7,$0-8
MOVQ inout+0(FP), DI
@@ -16,7 +18,7 @@
MOVQ 16(DI),CX
MOVQ 24(DI),R8
MOVQ 32(DI),R9
- MOVQ ·REDMASK51(SB),AX
+ MOVQ $REDMASK51,AX
MOVQ AX,R10
SUBQ $18,R10
MOVQ $3,R11
diff --git a/curve25519/ladderstep_amd64.s b/curve25519/ladderstep_amd64.s
index ee7b36c..7074e5c 100644
--- a/curve25519/ladderstep_amd64.s
+++ b/curve25519/ladderstep_amd64.s
@@ -7,6 +7,8 @@
// +build amd64,!gccgo,!appengine
+#include "const_amd64.h"
+
// func ladderstep(inout *[5][5]uint64)
TEXT ·ladderstep(SB),0,$296-8
MOVQ inout+0(FP),DI
@@ -118,7 +120,7 @@
MULQ 72(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -233,7 +235,7 @@
MULQ 32(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -438,7 +440,7 @@
MULQ 72(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -588,7 +590,7 @@
MULQ 32(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -728,7 +730,7 @@
MULQ 152(DI)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -843,7 +845,7 @@
MULQ 192(DI)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -993,7 +995,7 @@
MULQ 32(DI)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -1143,7 +1145,7 @@
MULQ 112(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
@@ -1329,7 +1331,7 @@
MULQ 192(SP)
ADDQ AX,R12
ADCQ DX,R13
- MOVQ ·REDMASK51(SB),DX
+ MOVQ $REDMASK51,DX
SHLQ $13,CX:SI
ANDQ DX,SI
SHLQ $13,R9:R8
diff --git a/curve25519/mul_amd64.s b/curve25519/mul_amd64.s
index 33ce57d..b162e65 100644
--- a/curve25519/mul_amd64.s
+++ b/curve25519/mul_amd64.s
@@ -7,6 +7,8 @@
// +build amd64,!gccgo,!appengine
+#include "const_amd64.h"
+
// func mul(dest, a, b *[5]uint64)
TEXT ·mul(SB),0,$16-24
MOVQ dest+0(FP), DI
@@ -121,7 +123,7 @@
MULQ 32(CX)
ADDQ AX,R14
ADCQ DX,R15
- MOVQ ·REDMASK51(SB),SI
+ MOVQ $REDMASK51,SI
SHLQ $13,R9:R8
ANDQ SI,R8
SHLQ $13,R11:R10
diff --git a/curve25519/square_amd64.s b/curve25519/square_amd64.s
index 3a92804..4e864a8 100644
--- a/curve25519/square_amd64.s
+++ b/curve25519/square_amd64.s
@@ -7,6 +7,8 @@
// +build amd64,!gccgo,!appengine
+#include "const_amd64.h"
+
// func square(out, in *[5]uint64)
TEXT ·square(SB),7,$0-16
MOVQ out+0(FP), DI
@@ -84,7 +86,7 @@
MULQ 32(SI)
ADDQ AX,R13
ADCQ DX,R14
- MOVQ ·REDMASK51(SB),SI
+ MOVQ $REDMASK51,SI
SHLQ $13,R8:CX
ANDQ SI,CX
SHLQ $13,R10:R9
