Changeset 242215 in webkit for trunk/Source/JavaScriptCore/offlineasm/cloop.rb

Timestamp:

Feb 28, 2019, 12:48:50 PM (6 years ago)

Author:

[email protected]

Message:

cloop.rb shift mask should depend on the word size being shifted.
​https://bugs.webkit.org/show_bug.cgi?id=195181
<rdar://problem/48484164>

Reviewed by Yusuke Suzuki.

Previously, we're always masking the shift amount with 0x1f. This is only correct
for 32-bit words. For 64-bit words, the mask should be 0x3f. For pointer sized
shifts, the mask depends on sizeof(uintptr_t).

• offlineasm/cloop.rb:

File:

• trunk/Source/JavaScriptCore/offlineasm/cloop.rb (modified) (2 diffs)

trunk/Source/JavaScriptCore/offlineasm/cloop.rb

@@ -1 @@
-# Copyright (C) 2012-2018 Apple Inc. All rights reserved.
+# Copyright (C) 2012-2019 Apple Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -427 +427 @@
         truncationFooter = ""
     end
-    $asm.putc "#{dst.clLValue(type)} = #{truncationHeader}#{operands[1].clValue(type)} #{operator} (#{operands[0].clValue(:int)} & 0x1f)#{truncationFooter};"
+    # FIXME: rename :int to :intptr to be match their expected names from C++. Ditto for :uint.
+    # https://bugs.webkit.org/show_bug.cgi?id=195183
+    shiftMask = "((sizeof(uintptr_t) == 8) ? 0x3f : 0x1f)" if type == :int || type == :uint
+    shiftMask = "0x3f" if type == :int64 || type == :uint64
+    shiftMask = "0x1f" if type == :int32 || type == :uint32
+    $asm.putc "#{dst.clLValue(type)} = #{truncationHeader}#{operands[1].clValue(type)} #{operator} (#{operands[0].clValue(:int)} & #{shiftMask})#{truncationFooter};"
 end