RFR: 8265917: Different values computed by C2 and interpreter/C1 for Math.pow(x, 2.0) on x86_32
jiefu at openjdk.java.net
Sun Apr 25 11:46:06 UTC 2021
C2 may produce different results for Math.pow(x, 2.0) compared with interpreter/C1 on x86_32.
E.g., for Math.pow(1.0 / 2047, 2.0):
The reason is that C2 will replace Math.pow(x, 2.0) with x*x.
However, there is no such optimization for interpreter/C1 on x86_32.
The fix just disables C2's opt for Math.pow(x, 2.0) on x86_32 since nobody (or very few people) would run x86_32.
And we don't have a plan to implement such opt on x86_32.
Another reason to fix this bug is that we need this patch to extend C2's opt for Math.pow(x, 0.5) on other platforms.
- 8265917: Different values computed by C2 and interpreter/C1 for Math.pow(x, 2.0) on x86_32
Stats: 60 lines in 2 files changed: 60 ins; 0 del; 0 mod
Fetch: git fetch https://git.openjdk.java.net/jdk pull/3677/head:pull/3677
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