Improve string indexing performance
Created attachment 55496 [details] Patch
Created attachment 55497 [details] Patch
Comment on attachment 55497 [details] Patch r=me
Committed r59056: <http://trac.webkit.org/changeset/59056>
Hi, I think the code in JIT::stringGetByValStubGenerator() may contain redundant code. Ex: ... #if USE(JSVALUE64) jit.zeroExtend32ToPtr(regT1, regT1); #else jit.emitFastArithImmToInt(regT1); #endif ... The same code appears in "JIT::emit_op_get_by_val()". So, we may execute one more time in stringGetByValStubGenerator(). I need to comment out jit.emitFastArithImmToInt(regT1) for MIPS to fix two new regressions. Otherwise, regT1 is shifted right by 1 bit (twice) and the index to a string is wrong. Thanks a lot! Ex: # svn diff JITPropertyAccess.cpp ... -#if USE(JSVALUE64) - jit.zeroExtend32ToPtr(regT1, regT1); -#else - jit.emitFastArithImmToInt(regT1); -#endif Regards, Chao-ying