AMD64HotSpot: emit jump to IC miss handler directly instead of emitting it inside verfied_entry
for empty methods we emitted something like this if a inline cache is needed:
prefix:
00: < IC check >
...
0b: jne <ic_miss_call>
11: nop
...
verified_entry:
20: ret
ic_miss_call:
21: jmp <entry of runtime function>
when a method is deoptimized, HotSpot patches the verified_entry (0x20) with a
jump to a stub that handles call-sites that has been made non-entrant. since this jump
is 5 bytes long, it will overwrite ic_miss_call and blow up every caller that
calls this method via the unverified entry (prefix).
the fix is to emit the jump to the runtime function inside the unverfied entry:
prefix:
00: < IC check >
...
0b: je <verified_entry>
11: jeq <entry of runtime function>
16: nop
...
verified_entry:
20: ret
| author |
Bernhard Urban <bernhard.urban@jku.at> |
| date |
Mon, 30 Sep 2013 09:32:18 +0200 |
| parents |
a61af66fc99e |
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line source |
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1 README:
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2 This file should be located at the top of the hotspot Mercurial repository.
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4 See http://openjdk.java.net/ for more information about the OpenJDK.
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5
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6 See ../README-builds.html for complete details on build machine requirements.
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7
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8 Simple Build Instructions:
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9
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10 cd make && gnumake
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11
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12 The files that will be imported into the jdk build will be in the "build"
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13 directory.
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