From 0b38b8b77ca6eef0006b1051f86df440fe5ab8dd Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 5 Nov 2019 11:13:03 +0000
Subject: [PATCH] math/mpx-mul4-*.S: Output expanded Montgomery factor in a
 sensible order.

The current order is (y'_0, y'_1; y''_0, y''_1), (y'_2, y'_3; y''_2,
y''_3), but while this makes sense in the context of SSE2, it's not
really very satisfactory as a common currency.  (In particular, if we
want to resolve the expanded factor into a value then we'll have to do
it by steam because the limb placements are irregular.)

Instead, fix the ordering in the test stubs so that the pieces come out
as (y'_0, y''_0; y'_1, y''_1), (y'_2, y''_2; y'_3, y''_3), which is
generally much better to work with outside of SSE2.

Of course, this only affects testing, not the actual code, so
performance is unchanged.
---
 math/mpx-mul4-amd64-sse2.S | 6 ++++++
 math/mpx-mul4-x86-sse2.S   | 6 ++++++
 math/t/mpx-mul4            | 6 +++---
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/math/mpx-mul4-amd64-sse2.S b/math/mpx-mul4-amd64-sse2.S
index 1c205a73..1c344f40 100644
--- a/math/mpx-mul4-amd64-sse2.S
+++ b/math/mpx-mul4-amd64-sse2.S
@@ -1601,6 +1601,8 @@ FUNC(test_mmul4)
 	testtop	r11
 	call	mmul4
 	testtail
+	pshufd	xmm10, xmm10, SHUF(0, 2, 1, 3)
+	pshufd	xmm11, xmm11, SHUF(0, 2, 1, 3)
 	movdqu	[r10 +  0], xmm10
 	movdqu	[r10 + 16], xmm11
 	testcarryout
@@ -1612,6 +1614,8 @@ FUNC(test_mmla4)
 	testtop	r11
 	call	mmla4
 	testtail
+	pshufd	xmm10, xmm10, SHUF(0, 2, 1, 3)
+	pshufd	xmm11, xmm11, SHUF(0, 2, 1, 3)
 	movdqu	[r10 +  0], xmm10
 	movdqu	[r10 + 16], xmm11
 	testcarryout
@@ -1623,6 +1627,8 @@ FUNC(test_mont4)
 	testtop
 	call	mont4
 	testtail
+	pshufd	xmm10, xmm10, SHUF(0, 2, 1, 3)
+	pshufd	xmm11, xmm11, SHUF(0, 2, 1, 3)
 	movdqu	[r10 +  0], xmm10
 	movdqu	[r10 + 16], xmm11
 	testcarryout
diff --git a/math/mpx-mul4-x86-sse2.S b/math/mpx-mul4-x86-sse2.S
index 7e7173fc..cdbdfaf7 100644
--- a/math/mpx-mul4-x86-sse2.S
+++ b/math/mpx-mul4-x86-sse2.S
@@ -1286,6 +1286,8 @@ FUNC(test_mmul4)
 	mov	edi, [BP + 28]
 	movdqa	xmm0, [SP + 64]
 	movdqa	xmm1, [SP + 80]
+	pshufd	xmm0, xmm0, SHUF(0, 2, 1, 3)
+	pshufd	xmm1, xmm1, SHUF(0, 2, 1, 3)
 	movdqu	[edi], xmm0
 	movdqu	[edi + 16], xmm1
 	testcarryout [BP + 24]
@@ -1302,6 +1304,8 @@ FUNC(test_mmla4)
 	mov	edi, [BP + 28]
 	movdqa	xmm0, [SP + 64]
 	movdqa	xmm1, [SP + 80]
+	pshufd	xmm0, xmm0, SHUF(0, 2, 1, 3)
+	pshufd	xmm1, xmm1, SHUF(0, 2, 1, 3)
 	movdqu	[edi], xmm0
 	movdqu	[edi + 16], xmm1
 	testcarryout [BP + 24]
@@ -1318,6 +1322,8 @@ FUNC(test_mont4)
 	mov	edi, [BP + 28]
 	movdqa	xmm0, [SP + 64]
 	movdqa	xmm1, [SP + 80]
+	pshufd	xmm0, xmm0, SHUF(0, 2, 1, 3)
+	pshufd	xmm1, xmm1, SHUF(0, 2, 1, 3)
 	movdqu	[edi], xmm0
 	movdqu	[edi + 16], xmm1
 	testcarryout [BP + 24]
diff --git a/math/t/mpx-mul4 b/math/t/mpx-mul4
index f2337b8d..1d8a741e 100644
--- a/math/t/mpx-mul4
+++ b/math/t/mpx-mul4
@@ -59,7 +59,7 @@ mmul4 {
     d3d2d1d0d7d6d5d4dbdad9d8dfdedddc # v
     546f97b132b6ca1d10d519b5ca6ab8a9 # m
     00000000000000000000000000000000 # zz
-    00006c00000012ad00009a8d0000630c0000f0840000979d000077a400000caa # yy
+    00006c0000009a8d000012ad0000630c0000f084000077a40000979d00000caa # yy
     0003126be83bdbf40002a05c4867918e000259dfe01b01770001b7e463bf6b7a00011339f770da470000bdab9990cf26; # cc
 }
 
@@ -70,7 +70,7 @@ mmla4 {
     d3d2d1d0d7d6d5d4dbdad9d8dfdedddc # v
     546f97b132b6ca1d10d519b5ca6ab8a9 # m
     00000000000000000000000000000000 # zz
-    000016b00000d85500000b390000507000008de20000754b000057700000c5db # yy
+    000016b000000b390000d8550000507000008de2000057700000754b0000c5db # yy
     000338658ad352110002f9fbc6cd85d5000205e99c5e20d300021acac7b997550000fdb10c111c11000131df2708bb59; # cc
 }
 
@@ -79,6 +79,6 @@ mont4 {
     acadaeafa8a9aaaba4a5a6a7a0a1a2a3 # n
     546f97b132b6ca1d10d519b5ca6ab8a9 # m
     00000000000000000000000000000000 # zz
-    0000aab00000c5a7000070ab0000ed6400009d5d0000ddad0000dfcb0000b930 # yy
+    0000aab0000070ab0000c5a70000ed6400009d5d0000dfcb0000ddad0000b930 # yy
     0001734705fa761d00019ee57a6290e40000f14fc045d61200010386c155e29100008b1816a19f2700007432ecd64990; # cc
 }
-- 
2.11.0