-
Bug
-
Resolution: Fixed
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P4
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11, 17, 18, 19
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b14
-
x86
| Issue | Fix Version | Assignee | Priority | Status | Resolution | Resolved In Build |
|---|---|---|---|---|---|---|
| JDK-8284264 | 18.0.2 | Tobias Hartmann | P4 | Resolved | Fixed | b02 |
| JDK-8283831 | 17.0.4-oracle | Tobias Hartmann | P4 | Resolved | Fixed | b01 |
| JDK-8284082 | 17.0.4 | Martin Doerr | P4 | Resolved | Fixed | b01 |
| JDK-8284054 | 11.0.16-oracle | Tobias Hartmann | P4 | Resolved | Fixed | b02 |
| JDK-8284517 | 11.0.16 | Goetz Lindenmaier | P4 | Resolved | Fixed | b01 |
Cursory examination of assembly shows that likely unnecessary vzeroupper instructions are emitted in a few places.
-prof perfasm of StringBuilders::charAtLatin1 on a Intel SandyBridge system (AVX=2 default):
c2, level 4, org.openjdk.bench.java.lang.StringBuilders::charAtLatin1, version 648 (91 bytes)
# {method} {0x00007f35abc73c50} 'charAtLatin1' '()C' in 'org/openjdk/bench/java/lang/StringBuilders'
# [sp+0x30] (sp of caller)
0x00007f35dd247e20: mov 0x8(%rsi),%r10d
0x00007f35dd247e24: movabs $0x800000000,%r11
0x00007f35dd247e2e: add %r11,%r10
0x00007f35dd247e31: cmp %r10,%rax
0x00007f35dd247e34: jne 0x00007f35d56c3780 ; {runtime_call ic_miss_stub}
0x00007f35dd247e3a: xchg %ax,%ax
0x00007f35dd247e3c: nopl 0x0(%rax)
[Verified Entry Point]
1.62% 0x00007f35dd247e40: mov %eax,-0x14000(%rsp)
10.14% 0x00007f35dd247e47: push %rbp
5.21% 0x00007f35dd247e48: sub $0x20,%rsp ;*synchronization entry
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@-1 (line 345)
0x00007f35dd247e4c: mov 0xc(%rsi),%r9d ;*getfield charAt_index {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@5 (line 345)
25.33% 0x00007f35dd247e50: mov 0x24(%rsi),%r11d ;*getfield sbLatin1 {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@1 (line 345)
0x00007f35dd247e54: mov 0xc(%r12,%r11,8),%r10d ; implicit exception: dispatches to 0x00007f35dd247f00
;*getfield count {reexecute=0 rethrow=0 return_oop=0}
; - java.lang.AbstractStringBuilder::charAt@2 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
0x00007f35dd247e59: test %r10d,%r10d
0x00007f35dd247e5c: jl 0x00007f35dd247ecc
0x00007f35dd247e5e: cmp %r10d,%r9d
╭ 0x00007f35dd247e61: jae 0x00007f35dd247e9c
2.89% │ 0x00007f35dd247e63: movsbl 0x10(%r12,%r11,8),%ebp ;*invokestatic checkIndex {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f35dd247e69: test %ebp,%ebp
│ 0x00007f35dd247e6b: jne 0x00007f35dd247ee8 ;*ifne {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::isLatin1@10 (line 1676)
│ ; - java.lang.AbstractStringBuilder::charAt@13 (line 353)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f35dd247e6d: mov 0x14(%r12,%r11,8),%ebp ;*getfield value {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@20 (line 354)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f35dd247e72: mov 0xc(%r12,%rbp,8),%r10d ; implicit exception: dispatches to 0x00007f35dd247f10
1.62% │ 0x00007f35dd247e77: cmp %r10d,%r9d
│ 0x00007f35dd247e7a: jae 0x00007f35dd247eb8
│ 0x00007f35dd247e7c: lea (%r12,%rbp,8),%r10
│ 0x00007f35dd247e80: movzbl 0x10(%r10,%r9,1),%eax ;*iand {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@28 (line 354)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
3.31% │ 0x00007f35dd247e86: vzeroupper
1.55% │ 0x00007f35dd247e89: add $0x20,%rsp
│ 0x00007f35dd247e8d: pop %rbp
│ 0x00007f35dd247e8e: cmp 0x338(%r15),%rsp ; {poll_return}
│ 0x00007f35dd247e95: ja 0x00007f35dd247f20
1.55% │ 0x00007f35dd247e9b: retq
↘ 0x00007f35dd247e9c: mov $0xffffffe4,%esi
0x00007f35dd247ea1: mov %r11d,%ebp
0x00007f35dd247ea4: mov %r9d,0x4(%rsp)
0x00007f35dd247ea9: mov %r10d,0x8(%rsp)
0x00007f35dd247eae: xchg %ax,%ax
0x00007f35dd247eb0: vzeroupper
0x00007f35dd247eb3: callq 0x00007f35d56c9000 ; ImmutableOopMap {rbp=NarrowOop }
;*invokestatic checkIndex {reexecute=0 rethrow=0 return_oop=0}
; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
UseAVX=0|1 improves microbenchmark score by 1.2ns/op (~1.06x):
UseAVX=1
c2, level 4, org.openjdk.bench.java.lang.StringBuilders::charAtLatin1, version 647 (88 bytes)
# {method} {0x00007f5687873c50} 'charAtLatin1' '()C' in 'org/openjdk/bench/java/lang/StringBuilders'
# [sp+0x30] (sp of caller)
0x00007f56b92471a0: mov 0x8(%rsi),%r10d
0x00007f56b92471a4: movabs $0x800000000,%r11
0x00007f56b92471ae: add %r11,%r10
0x00007f56b92471b1: cmp %r10,%rax
0x00007f56b92471b4: jne 0x00007f56b16c3780 ; {runtime_call ic_miss_stub}
0x00007f56b92471ba: xchg %ax,%ax
0x00007f56b92471bc: nopl 0x0(%rax)
[Verified Entry Point]
1.71% 0x00007f56b92471c0: mov %eax,-0x14000(%rsp)
11.09% 0x00007f56b92471c7: push %rbp
7.29% 0x00007f56b92471c8: sub $0x20,%rsp ;*synchronization entry
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@-1 (line 345)
0x00007f56b92471cc: mov 0xc(%rsi),%r9d ;*getfield charAt_index {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@5 (line 345)
28.14% 0x00007f56b92471d0: mov 0x24(%rsi),%r11d ;*getfield sbLatin1 {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@1 (line 345)
0x00007f56b92471d4: mov 0xc(%r12,%r11,8),%r10d ; implicit exception: dispatches to 0x00007f56b924726c
;*getfield count {reexecute=0 rethrow=0 return_oop=0}
; - java.lang.AbstractStringBuilder::charAt@2 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
0x00007f56b92471d9: test %r10d,%r10d
0x00007f56b92471dc: jl 0x00007f56b9247240
0x00007f56b92471de: cmp %r10d,%r9d
╭ 0x00007f56b92471e1: jae 0x00007f56b9247219
3.21% │ 0x00007f56b92471e3: movsbl 0x10(%r12,%r11,8),%ebp ;*invokestatic checkIndex {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f56b92471e9: test %ebp,%ebp
│ 0x00007f56b92471eb: jne 0x00007f56b9247258 ;*ifne {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::isLatin1@10 (line 1676)
│ ; - java.lang.AbstractStringBuilder::charAt@13 (line 353)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f56b92471ed: mov 0x14(%r12,%r11,8),%ebp ;*getfield value {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@20 (line 354)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
│ 0x00007f56b92471f2: mov 0xc(%r12,%rbp,8),%r10d ; implicit exception: dispatches to 0x00007f56b924727c
1.64% │ 0x00007f56b92471f7: cmp %r10d,%r9d
│ 0x00007f56b92471fa: jae 0x00007f56b9247230
│ 0x00007f56b92471fc: lea (%r12,%rbp,8),%r10
│ 0x00007f56b9247200: movzbl 0x10(%r10,%r9,1),%eax ;*iand {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@28 (line 354)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
3.45% │ 0x00007f56b9247206: add $0x20,%rsp
│ 0x00007f56b924720a: pop %rbp
│ 0x00007f56b924720b: cmp 0x338(%r15),%rsp ; {poll_return}
│ 0x00007f56b9247212: ja 0x00007f56b924728c
1.74% │ 0x00007f56b9247218: retq
↘ 0x00007f56b9247219: mov $0xffffffe4,%esi
0x00007f56b924721e: mov %r11d,%ebp
0x00007f56b9247221: mov %r9d,0x4(%rsp)
0x00007f56b9247226: mov %r10d,0x8(%rsp)
0x00007f56b924722b: callq 0x00007f56b16c9000 ; ImmutableOopMap {rbp=NarrowOop }
;*invokestatic checkIndex {reexecute=0 rethrow=0 return_oop=0}
; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
; - org.openjdk.bench.java.lang.StringBuilders::charAtLatin1@8 (line 345)
; {runtime_call UncommonTrapBlob}
Disabling the Preconditions_checkIndex intrinsic improves benchmark score similarly, but with slightly different code shape:
c2, level 4, org.openjdk.bench.java.lang.StringBuilders::charAtUtf16, version 658 (77 bytes)
# {method} {0x00007fe485c73d18} 'charAtUtf16' '()C' in 'org/openjdk/bench/java/lang/StringBuilders'
# [sp+0x40] (sp of caller)
0x00007fe4b124a020: mov 0x8(%rsi),%r10d
0x00007fe4b124a024: movabs $0x800000000,%r11
0x00007fe4b124a02e: add %r11,%r10
0x00007fe4b124a031: cmp %r10,%rax
0x00007fe4b124a034: jne 0x00007fe4a96c3780 ; {runtime_call ic_miss_stub}
0x00007fe4b124a03a: xchg %ax,%ax
0x00007fe4b124a03c: nopl 0x0(%rax)
[Verified Entry Point]
2.74% 0x00007fe4b124a040: mov %eax,-0x14000(%rsp)
9.91% 0x00007fe4b124a047: push %rbp
6.59% 0x00007fe4b124a048: sub $0x30,%rsp ;*synchronization entry
; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@-1 (line 351)
0x00007fe4b124a04c: mov 0xc(%rsi),%ecx ;*getfield charAt_index {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@5 (line 351)
12.96% 0x00007fe4b124a04f: mov 0x28(%rsi),%r11d ;*getfield sbUtf16 {reexecute=0 rethrow=0 return_oop=0}
; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@1 (line 351)
0x00007fe4b124a053: mov 0xc(%r12,%r11,8),%r10d ; implicit exception: dispatches to 0x00007fe4b124a0e4
;*getfield count {reexecute=0 rethrow=0 return_oop=0}
; - java.lang.AbstractStringBuilder::charAt@2 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
0x00007fe4b124a058: test %ecx,%ecx
╭ 0x00007fe4b124a05a: jl 0x00007fe4b124a08e ;*iflt {reexecute=0 rethrow=0 return_oop=0}
│ ; - jdk.internal.util.Preconditions::checkIndex@1 (line 301)
│ ; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
1.42% │ 0x00007fe4b124a05c: cmp %r10d,%ecx
│ 0x00007fe4b124a05f: jge 0x00007fe4b124a0a8 ;*if_icmplt {reexecute=0 rethrow=0 return_oop=0}
│ ; - jdk.internal.util.Preconditions::checkIndex@6 (line 301)
│ ; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
1.80% │ 0x00007fe4b124a061: movsbl 0x10(%r12,%r11,8),%r8d ;*getfield coder {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::isLatin1@7 (line 1676)
│ ; - java.lang.AbstractStringBuilder::charAt@13 (line 353)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
│ 0x00007fe4b124a067: test %r8d,%r8d
│ 0x00007fe4b124a06a: je 0x00007fe4b124a0c4 ;*ifeq {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@16 (line 353)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
│ 0x00007fe4b124a06c: mov 0x14(%r12,%r11,8),%r11d ;*getfield value {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@32 (line 356)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
│ 0x00007fe4b124a071: lea (%r12,%r11,8),%r10
1.77% │ 0x00007fe4b124a075: movzwl 0x10(%r10,%rcx,2),%eax ;*invokestatic getChar {reexecute=0 rethrow=0 return_oop=0}
│ ; - java.lang.AbstractStringBuilder::charAt@36 (line 356)
│ ; - java.lang.StringBuilder::charAt@2 (line 87)
│ ; - org.openjdk.bench.java.lang.StringBuilders::charAtUtf16@8 (line 351)
5.96% │ 0x00007fe4b124a07b: add $0x30,%rsp
│ 0x00007fe4b124a07f: pop %rbp
│ 0x00007fe4b124a080: cmp 0x338(%r15),%rsp ; {poll_return}
│ 0x00007fe4b124a087: ja 0x00007fe4b124a0f0
1.56% │ 0x00007fe4b124a08d: retq
↘ 0x00007fe4b124a08e: mov $0xffffff45,%esi
0x00007fe4b124a093: mov %r11d,%ebp
0x00007fe4b124a096: mov %ecx,0x4(%rsp)
0x00007fe4b124a09a: mov %r10d,0x8(%rsp)
0x00007fe4b124a09f: mov %ecx,0xc(%rsp)
0x00007fe4b124a0a3: callq 0x00007fe4a96c9000 ; ImmutableOopMap {rbp=NarrowOop }
;*iflt {reexecute=1 rethrow=0 return_oop=0}
; - (reexecute) jdk.internal.util.Preconditions::checkIndex@1 (line 301)
; - java.lang.AbstractStringBuilder::charAt@8 (line 352)
; - java.lang.StringBuilder::charAt@2 (line 87)
- backported by
-
JDK-8283831 Suboptimal code generation around Preconditions.checkIndex intrinsic with AVX2
-
- Resolved
-
-
-
- Resolved
-
-
-
- Resolved
-
-
-
- Resolved
-
-
-
- Resolved
-
- relates to
-
JDK-8268698 Use Objects.check{Index,FromToIndex,FromIndexSize} for java.base
-
- Resolved
-
- links to
-
Commit
openjdk/jdk11u-dev/1f011cbb
-
Commit
openjdk/jdk17u-dev/079119ab
-
Commit
openjdk/jdk18u/84441e67
-
Commit
openjdk/jdk/88f0938c
-
Review
openjdk/jdk11u-dev/1012
-
Review
openjdk/jdk17u-dev/305
-
Review
openjdk/jdk18u/61
-
Review
openjdk/jdk/7770
(1 relates to, 8 links to)