From 6d19758a40dc72b380d2284a659b5d126354c1cb Mon Sep 17 00:00:00 2001
Message-Id: <6d19758a40dc72b380d2284a659b5d126354c1cb.1716360580.git.mdw@distorted.org.uk>
From: Mark Wooding <mdw@chiark.greenend.org.uk>
Date: Wed, 4 Jan 2017 01:41:22 +0000
Subject: [PATCH] math/mpx-mul4-x86-sse2.S: Maintain a local copy of the
 counter.
Organization: Straylight/Edgeware

From: Mark Wooding <mdw@distorted.org.uk>

I've no idea whether one's allowed to mutate a parameter passed on the
stack.  Play it safe.

This means that (a) the counter is now in a fixed place in the frame so
that `testtail' doesn't need to be told where it is, an (b)
`testprologue' needs to initialize it from the caller's parameter, so it
needs to grow a macro argument.
---
 math/mpx-mul4-x86-sse2.S | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/math/mpx-mul4-x86-sse2.S b/math/mpx-mul4-x86-sse2.S
index 14052fd0..f6c81673 100644
--- a/math/mpx-mul4-x86-sse2.S
+++ b/math/mpx-mul4-x86-sse2.S
@@ -1068,7 +1068,7 @@ ENDFUNC
 	mov	[ebx + ecx*8 + 4], edx
 .endm
 
-.macro	testprologue
+.macro	testprologue n
 	pushreg	ebp
 	pushreg	ebx
 	pushreg	esi
@@ -1077,11 +1077,14 @@ ENDFUNC
 	and	esp, ~15
 	sub	esp, 3*32 + 4*4
   endprologue
+	mov	eax, \n
+	mov	[esp + 104], eax
 	// vars:
 	//	esp +   0 = v expanded
 	//	esp +  32 = y expanded
 	//	esp +  64 = ? expanded
 	//	esp +  96 = cycles
+	//	esp + 104 = count
 .endm
 
 .macro	testepilogue
@@ -1139,8 +1142,8 @@ ENDFUNC
   .endif
 .endm
 
-.macro	testtail cyv, n
-	cystore	esp + 96, \cyv, \n
+.macro	testtail cyv
+	cystore	esp + 96, \cyv, esp + 104
 	jnz	0b
 .endm
 
@@ -1152,60 +1155,60 @@ ENDFUNC
 .endm
 
 FUNC(test_dmul4)
-	testprologue
+	testprologue [ebp + 44]
 	testldcarry [ebp + 24]
 	testexpand [ebp + 36], [ebp + 40]
 	mov	edi, [ebp + 20]
 	testtop	[ebp + 28], [ebp + 32]
 	call	dmul4
-	testtail [ebp + 48], [ebp + 44]
+	testtail [ebp + 48]
 	testcarryout [ebp + 24]
 	testepilogue
 ENDFUNC
 
 FUNC(test_dmla4)
-	testprologue
+	testprologue [ebp + 44]
 	testldcarry [ebp + 24]
 	testexpand [ebp + 36], [ebp + 40]
 	mov	edi, [ebp + 20]
 	testtop	[ebp + 28], [ebp + 32]
 	call	dmla4
-	testtail [ebp + 48], [ebp + 44]
+	testtail [ebp + 48]
 	testcarryout [ebp + 24]
 	testepilogue
 ENDFUNC
 
 FUNC(test_mul4)
-	testprologue
+	testprologue [ebp + 36]
 	testldcarry [ebp + 24]
 	testexpand nil, [ebp + 32]
 	mov	edi, [ebp + 20]
 	testtop	nil, [ebp + 28]
 	call	mul4
-	testtail [ebp + 40], [ebp + 36]
+	testtail [ebp + 40]
 	testcarryout [ebp + 24]
 	testepilogue
 ENDFUNC
 
 FUNC(test_mla4)
-	testprologue
+	testprologue [ebp + 36]
 	testldcarry [ebp + 24]
 	testexpand nil, [ebp + 32]
 	mov	edi, [ebp + 20]
 	testtop	nil, [ebp + 28]
 	call	mla4
-	testtail [ebp + 40], [ebp + 36]
+	testtail [ebp + 40]
 	testcarryout [ebp + 24]
 	testepilogue
 ENDFUNC
 
 FUNC(test_mmul4)
-	testprologue
+	testprologue [ebp + 48]
 	testexpand [ebp + 40], [ebp + 44]
 	mov	edi, [ebp + 20]
 	testtop	[ebp + 32], [ebp + 36], mont
 	call	mmul4
-	testtail [ebp + 52], [ebp + 48]
+	testtail [ebp + 52]
 	mov	edi, [ebp + 28]
 	movdqa	xmm0, [esp + 64]
 	movdqa	xmm1, [esp + 80]
@@ -1216,12 +1219,12 @@ FUNC(test_mmul4)
 ENDFUNC
 
 FUNC(test_mmla4)
-	testprologue
+	testprologue [ebp + 48]
 	testexpand [ebp + 40], [ebp + 44]
 	mov	edi, [ebp + 20]
 	testtop	[ebp + 32], [ebp + 36], mont
 	call	mmla4
-	testtail [ebp + 52], [ebp + 48]
+	testtail [ebp + 52]
 	mov	edi, [ebp + 28]
 	movdqa	xmm0, [esp + 64]
 	movdqa	xmm1, [esp + 80]
@@ -1232,12 +1235,12 @@ FUNC(test_mmla4)
 ENDFUNC
 
 FUNC(test_mont4)
-	testprologue
+	testprologue [ebp + 40]
 	testexpand nil, [ebp + 36]
 	mov	edi, [ebp + 20]
 	testtop	nil, [ebp + 32], mont
 	call	mont4
-	testtail [ebp + 44], [ebp + 40]
+	testtail [ebp + 44]
 	mov	edi, [ebp + 28]
 	movdqa	xmm0, [esp + 64]
 	movdqa	xmm1, [esp + 80]
-- 
[mdw]