diff --git a/simd/jdmrgss2-64.asm b/simd/jdmrgss2-64.asm
index 36e25822..ba3de350 100644
--- a/simd/jdmrgss2-64.asm
+++ b/simd/jdmrgss2-64.asm
@@ -12,7 +12,7 @@
 ; This file should be assembled with NASM (Netwide Assembler),
 ; can *not* be assembled with Microsoft's MASM or any compatible
 ; assembler (including Borland's Turbo Assembler).
-; NASM is available from http://nasm.sourceforge.net/ for
+; NASM is available from http://nasm.sourceforge.net/ or
 ; http://sourceforge.net/project/showfiles.php?group_id=6208
 ;
 ; [TAB8]
diff --git a/simd/jdmrgss2.asm b/simd/jdmrgss2.asm
index 6a0dbd91..a00e5398 100644
--- a/simd/jdmrgss2.asm
+++ b/simd/jdmrgss2.asm
@@ -478,9 +478,9 @@ EXTN(jsimd_h2v1_merged_upsample_sse2):
 	cmp	ecx, byte SIZEOF_XMMWORD/8
 	jb	short .column_st7
 	movq	MMWORD [edi], xmmA
-	add	edi, byte SIZEOF_XMMWORD/2
+	add	edi, byte SIZEOF_XMMWORD/8*4
 	sub	ecx, byte SIZEOF_XMMWORD/8
-	psrldq	xmmA, 64
+	psrldq	xmmA, SIZEOF_XMMWORD/8*4
 .column_st7:
 	; Store one pixel (4 bytes) of xmmA to the output when it has enough
 	; space.