[SPIR-V] Handle unreferenced globals at the main GlobalISel phases. #66
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Introduce 'unref_global' intrinsic for that purpose. Empty modules (i.e. w/o any functions) are not processed, think we should't do that at all, fixed the LIT.
Probably yes, but as I see SPIRV documentation does not prohibit modules without functions. And spirv-val does not report a problem on such spv files. Are you sure that such modules (without entry points) are not used for example in CTS tests? Another test with no functions: transcoding/global-constant-expression.ll |
| @@ -259,6 +259,12 @@ bool SPIRVPreTranslationLegalizer::runOnFunction(Function *Func, | |||
| InitInst->setArgOperand(1, Init); | |||
| InitConsts.insert(Init); | |||
| } | |||
| if ((!GV.hasInitializer() || isa<UndefValue>(GV.getInitializer())) && | |||
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By the way why do you check that a GV does not have init value before creating call to spv_unref_global? I suppose referenced GV may be initialized (see transcoding/global-constant-expression.ll).
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Need to double-check, but I suppose initialized unreferenced globals may be already handled by the 'global_init" intrinsic.
This may be handled by creating a fake function w/o emitting it. I just don't like the idea of arbitrary code generation in various passes as the hoisting one in this case |
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Oops, I wanted to postpone merging of this until we agreed on the approach, but it's ok, will do that in place. |
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Sorry for inconvenience. |
Introduce 'unref_global' intrinsic for that purpose.
Empty modules (i.e. w/o any functions) are not processed,
think we should't do that at all, fixed the LIT.