Request for reviews (L): 7063628: Use cbcond on T4 (original) (raw)

Vladimir Kozlov vladimir.kozlov at oracle.com
Thu Jul 14 15:27:51 PDT 2011

You are absolutely right. I will change the code to this:

// Do the emission.

And I will move the assert into labelOper::label(). It works on x86 and sparc so I will remove asserts I added and I will cleanup "l ? (l->loc_pos()".

Thanks, Vladimir

Tom Rodriguez wrote:

compile.cpp:

+ if (n->isBranch() && n->asMach()->idealOpcode() != OpJump) { + // Fake label for branch instruction. + MacroAssembler masm(&buf); + Label fakeL; + masm.bind(fakeL); + n->asMach()->labelset(fakeL, 0); + } The label be cleared after doing the emit too so we don't end up with garbage in there. tom What guarantees do we get about the lifetime of the storage for fakeL since it doesn't appear to be used? I would assume that at a minimum it should be declared outside of the if. You can clean up all the "l ? (l->locpos() - (cbuf.instssize() + 1)) : 0;" code in x86*.ad after this fix too. We can even use the MacroAssembler for these instrutions now if we want to though that's probably for another day. Should labelOper::label have an assert that it's non-null when called? That would cover all the other asserts you added though I'm not sure it must be true. The overall change looks good. tom

On Jul 13, 2011, at 8:44 PM, Vladimir Kozlov wrote: http://cr.openjdk.java.net/~kvn/7063628/webrev Fixed 7063628: Use cbcond on T4 Added new MacroAssembler instructions cmpandbr() and old branch instructions are modified to use cbcond on T4 if distance is small (2K bytes). Most of the rest changes are usage of these new branch instructions in Interpreter and C1. The prototype was done by Tom and I took some of his additional fixes. The formssel.cpp change is a bug fix where the MatchNode equality test wasn't recursing so it would mistakenly return true for complex matches. Added a fake label for branches generated in temp buffer by MachNode::emitsize(), added assert into .ad files to check label. There was problem in isinwdisp16range() (and in initial implementation of usecbc()) which calls target(L) before emitting branch. Non-bound (forward branch) labels record current pc() as a branch address and later try to patch instruction (which could be 'cmp') at that address. Removed unused code in checkklasssubtypefastpath(). Modified vmversion string: has prefix is removed and only v8 or v9 will be printed as well only niagaraplus or niagara. Tested on T4 with CTW, nsk, VM and java invoke regression tests.

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