From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 29 Dec 2016 15:24:56 +0000 (+0000)
Subject: math/mpx-mul4-x86-sse2.S: Additional piece of commentary.
X-Git-Tag: 2.3.0~6
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/ba12677b3295b30e8d331bed84e87e7cf261239a

math/mpx-mul4-x86-sse2.S: Additional piece of commentary.
---

diff --git a/math/mpx-mul4-x86-sse2.S b/math/mpx-mul4-x86-sse2.S
index 5d5714da..5d80860d 100644
--- a/math/mpx-mul4-x86-sse2.S
+++ b/math/mpx-mul4-x86-sse2.S
@@ -550,6 +550,9 @@ INTFUNC(mmla4)
 	movd	xmm5, [edi +  4]
 	movd	xmm6, [edi +  8]
 	movd	xmm7, [edi + 12]
+
+	// Calculate W = U V, and leave it in the destination.  Stash the
+	// carry pieces for later.
 	mulacc	[eax +  0], ecx, xmm4, xmm5, xmm6, xmm7
 	propout	[edi +  0],	 xmm4, xmm5