fix incorrect output / undefined behavior in Windows SSE2 assembly

The SSE2 patch introduced xmm10 as a temporary register for one of the rotations, but xmm6-xmm15 are callee-save registers on Windows, and SSE4.1 was only saving the registers it used. The minimal fix is to use one of the saved registers instead of xmm10. See BLAKE3-team#206.
ITS-AT-dev · Nov 5, 2021 · 1e50092 · 1e50092
1 parent d4a3209
commit 1e50092
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 12 deletions.
diff --git a/blake3_sse2_x86-64_windows_gnu.S b/blake3_sse2_x86-64_windows_gnu.S
@@ -2137,10 +2137,10 @@ _blake3_compress_in_place_sse2:
         por     xmm9, xmm8
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        movdqa  xmm10, xmm6
+        movdqa  xmm14, xmm6
         pand    xmm8, xmmword ptr [PBLENDW_0x3F_MASK+rip]
-        pand    xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
-        por     xmm8, xmm10
+        pand    xmm14, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        por     xmm8, xmm14
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2268,10 +2268,10 @@ blake3_compress_xof_sse2:
         por     xmm9, xmm8
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        movdqa  xmm10, xmm6
+        movdqa  xmm14, xmm6
         pand    xmm8, xmmword ptr [PBLENDW_0x3F_MASK+rip]
-        pand    xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
-        por     xmm8, xmm10
+        pand    xmm14, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        por     xmm8, xmm14
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5

diff --git a/blake3_sse2_x86-64_windows_msvc.asm b/blake3_sse2_x86-64_windows_msvc.asm
@@ -2139,10 +2139,10 @@ _blake3_compress_in_place_sse2 PROC
         por     xmm9, xmm8
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        movdqa  xmm10, xmm6
+        movdqa  xmm14, xmm6
         pand    xmm8, xmmword ptr [PBLENDW_0x3F_MASK]
-        pand    xmm10, xmmword ptr [PBLENDW_0xC0_MASK]
-        por     xmm8, xmm10
+        pand    xmm14, xmmword ptr [PBLENDW_0xC0_MASK]
+        por     xmm8, xmm14
         pshufd  xmm8, xmm8, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2271,10 +2271,10 @@ _blake3_compress_xof_sse2 PROC
         por     xmm9, xmm8
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        movdqa  xmm10, xmm6
+        movdqa  xmm14, xmm6
         pand    xmm8, xmmword ptr [PBLENDW_0x3F_MASK]
-        pand    xmm10, xmmword ptr [PBLENDW_0xC0_MASK]
-        por     xmm8, xmm10
+        pand    xmm14, xmmword ptr [PBLENDW_0xC0_MASK]
+        por     xmm8, xmm14
         pshufd  xmm8, xmm8, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5