RFR: 8358592: Assert in Assembler::ptest due to missing SSE42 support [v2]

Guanqiang Han duke at openjdk.org
Wed Jul 9 04:32:46 UTC 2025


> Setting "-XX:UseSSE=1" in command line prevents the code from entering the block shown below, which causes UseSSE42Intrinsics to not be correctly set. Because supports_sse3() return false.
> ![图片1](https://github.com/user-attachments/assets/d3cdb1fe-f0e0-41dc-98c9-4427eaffdb0e)
> in addition , setting "-XX:+UseSSE42Intrinsics" in command line set UseVectorizedMismatchIntrinsic to True shown below.
> ![图片2](https://github.com/user-attachments/assets/bbe623a3-453a-483d-b34c-1cdb394f2d4e)
> The above code causes the ptest instruction to be invoked.
> The assertion "assert(VM_Version::supports_sse4_1() || VM_Version::supports_avx(), "")" in ptest was triggered and caused the crash because of the following reason:
> Setting "-XX:UseSSE=1" in command line  cause "CPU_SSE4_1" was cleared and cause "VM_Version::supports_sse4_1()" return false ,related code as below:
> ![图片3](https://github.com/user-attachments/assets/e9a8a690-dd4d-4216-b09f-be8439a9a73b)
> Setting "-XX:UseSSE=1" in command line  cause "UseAVX=0" and cause "VM_Version::supports_avx()" return false ,related code as below:
> ![image](https://github.com/user-attachments/assets/6d9e770b-0a7a-43cd-a4bc-d15247f6478e)
> all of these above cause this issue.
> i fix this issue by correcting UseSSE42Intrinsics to false when "UseSSE" in command line was set to 1, so that UseVectorizedMismatchIntrinsic will be set false and ptest was not triggered.

Guanqiang Han has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - add regression test for JDK-8358592
 - Merge remote-tracking branch 'upstream/master' into 8358592
 - 8358592: Assert in Assembler::ptest due to missing SSE42 support
   
   Setting "-XX:UseSSE=1" in command line prevents the code from entering the block which causes UseSSE42Intrinsics to not be correctly set.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/26151/files
  - new: https://git.openjdk.org/jdk/pull/26151/files/90bad7d6..0684264c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26151&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26151&range=00-01

  Stats: 3048 lines in 159 files changed: 1515 ins; 714 del; 819 mod
  Patch: https://git.openjdk.org/jdk/pull/26151.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26151/head:pull/26151

PR: https://git.openjdk.org/jdk/pull/26151


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