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Name resolution #16

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NalaGinrut opened this issue May 3, 2020 · 12 comments · Fixed by #24
Closed

Name resolution #16

NalaGinrut opened this issue May 3, 2020 · 12 comments · Fixed by #24
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@NalaGinrut
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The resolution rules are not well documented in Rust doc, the rustc relies on librustc_resolve.

I'm going to list all the rules here (or wiki) for the reference.
@NalaGinrut
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NalaGinrut commented May 3, 2020 •
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  • Traverse AST top-down and resolve every encountered name.
  • The situation that new scope should be added:
    • A block enclosing with curly braces
    • Let binding
    • Hygiene macro
  • The rustc introduced a concept of Ribs to include all these kinds of scopes. Each Ribs maintain its own stack for storing the scopes. I think this can be implemented by a base class Scope. Maybe we don't have to reinvent a new concept.
  • These items have their own namespace, so the identifier is NOT unique among them:
    • Types
    • Values
    • Macros.

@bjorn3
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bjorn3 commented May 3, 2020

The RFC for the current name resolution is: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md

@NalaGinrut
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Oh nice! That's what we need, I googled an obsoleted result. Thanks!

@NalaGinrut
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NalaGinrut commented May 5, 2020 •
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I think we should also add an option to dump the AST after the resolution, for debugging the resolution.

@philberty
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I agree we can reuse the same command line option and i think dumping to file would be really helpful aswell lets makea new issue to dump to file instead of console

@bjorn3
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bjorn3 commented May 5, 2020

Rustc has several versions of this: rustc -Zunpretty=help

@NalaGinrut
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NalaGinrut commented May 5, 2020 •
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@bjorn3 nice to know it, however, -Z seems only for nightly.

@philberty If you just want to output the current result to a file with an option, I think it's just a few lines code. It's possible to refactor the current dump framework to support multiple dump format, and even for a different stage of the pipeline, but I don't think it's our current work. Anyway it's a good idea to add to TODO.

@NalaGinrut
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The resolution relies on macro expansion, so I'm starting to work on macros parallelly. #17

@philberty philberty linked a pull request May 17, 2020 that will close this issue
Phil/compilation simple #24
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@philberty philberty reopened this May 20, 2020
@philberty
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Sorry for the closed issues i wanted to see if tagging commits linked them to issues but it seems to just close them instead

@philberty philberty added the plan label Dec 18, 2020
@philberty philberty added this to the Core Datastructures milestone Dec 18, 2020
@philberty philberty removed this from the Core Datastructures milestone Jan 6, 2021
philberty pushed a commit that referenced this issue Mar 3, 2021
@TamarChristinaArm
Arm: Add NEON and MVE complex mul, mla and mls patterns.
389b67f 
This adds implementation for the optabs for complex operations.  With this the
following C code:

  void g (float complex a[restrict N], float complex b[restrict N],
	  float complex c[restrict N])
  {
    for (int i=0; i < N; i++)
      c[i] =  a[i] * b[i];
  }

generates

NEON:

g:
        vmov.f32        q11, #0.0  @ v4sf
        add     r3, r2, #1600
.L2:
        vmov    q8, q11  @ v4sf
        vld1.32 {q10}, [r1]!
        vld1.32 {q9}, [r0]!
        vcmla.f32       q8, q9, q10, #0
        vcmla.f32       q8, q9, q10, #90
        vst1.32 {q8}, [r2]!
        cmp     r3, r2
        bne     .L2
        bx      lr

MVE:

g:
        push    {lr}
        mov     lr, #100
        dls     lr, lr
.L2:
        vldrw.32        q1, [r1], #16
        vldrw.32        q2, [r0], #16
        vcmul.f32       q3, q2, q1, #0
        vcmla.f32       q3, q2, q1, #90
        vstrw.32        q3, [r2], #16
        le      lr, .L2
        ldr     pc, [sp], #4

instead of

g:
        add     r3, r2, #1600
.L2:
        vld2.32 {d20-d23}, [r0]!
        vld2.32 {d16-d19}, [r1]!
        vmul.f32        q14, q11, q9
        vmul.f32        q15, q11, q8
        vneg.f32        q14, q14
        vfma.f32        q15, q10, q9
        vfma.f32        q14, q10, q8
        vmov    q13, q15  @ v4sf
        vmov    q12, q14  @ v4sf
        vst2.32 {d24-d27}, [r2]!
        cmp     r3, r2
        bne     .L2
        bx      lr

and

g:
        add     r3, r2, #1600
.L2:
        vld2.32 {d20-d23}, [r0]!
        vld2.32 {d16-d19}, [r1]!
        vmul.f32        q15, q10, q8
        vmul.f32        q14, q10, q9
        vmls.f32        q15, q11, q9
        vmla.f32        q14, q11, q8
        vmov    q12, q15  @ v4sf
        vmov    q13, q14  @ v4sf
        vst2.32 {d24-d27}, [r2]!
        cmp     r3, r2
        bne     .L2
        bx      lr

respectively.

gcc/ChangeLog:

	* config/arm/iterators.md (rotsplit1, rotsplit2, conj_op, fcmac1,
	VCMLA_OP, VCMUL_OP): New.
	* config/arm/mve.md (mve_vcmlaq<mve_rot><mode>): Support vec_dup 0.
	* config/arm/neon.md (cmul<conj_op><mode>3): New.
	* config/arm/unspecs.md (UNSPEC_VCMLA_CONJ, UNSPEC_VCMLA180_CONJ,
	UNSPEC_VCMUL_CONJ): New.
	* config/arm/vec-common.md (cmul<conj_op><mode>3, arm_vcmla<rot><mode>,
	cml<fcmac1><conj_op><mode>4): New.
@philberty
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Closing this as there is documentation available over on the wiki for name resolution

@bjorn3
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bjorn3 commented Mar 15, 2021

Did you forget to close this?

@philberty
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Thanks, Again we are following rustc more documentation will be added to the wiki over time. See -frust-dump-all for debug outputs and this diagram.

image

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Phil/compilation simple Rust-GCC/gccrs
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@NalaGinrut @philberty @bjorn3