Commit Graph

123 Commits

Author SHA1 Message Date
John Stiles
e1182785be Create a diagonal-matrix Constructor class.
This constructor takes a single argument and splats it diagonally across
an otherwise-zero matrix. These are also sometimes referred to as a
uniform-scale matrix.

Change-Id: I1ed8140f55f5cad4029015807b220d6475401daa
Bug: skia:11032
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/390716
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-31 18:00:42 +00:00
John Stiles
8037c9e2ed Add test for folding of == and != for arrays.
We don't directly support this today at all. In practice, though, simple
constant arrays are detected as equal in the constant-folding pass
because they hit the `x == x` self-equality check (using
`IsSameExpressionTree`).

This does not work for our inequality tests, though, so those do not
fold.

Change-Id: I6730a9a2d1da9ac613ee58889d651f3ff65b1d2d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/391057
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-31 15:32:03 +00:00
John Stiles
fabed8bb79 Fix fuzzer-discovered error with variable declarations.
As soon as a single VarDeclaration is successfully created, its Variable
is added to the current symbol table. However, if a variable-declaration
line declared several variables in a row, we would stop if ANY of the
declarations contained an error and discard the entire statement, but
would continue processing the rest of the program. This left us in a
position where some Variables existed in the SymbolTable with valid,
reachable names, but their corresponding VarDeclaration statement had
been thrown away as erroneous. Since Variables point back to
VarDeclarations for their initialValues, this gave us a stale pointer.
Any future reference to that variable name which could trigger an
access to its initialValue would read from this dead pointer.

This CL fixes the conversion of VarDeclarations so that we no longer
throw away any VarDeclarations associated with a successfully-parsed
Variable.

Change-Id: If8ec3c160933e48a0e1f36414234b3a849d8978c
Bug: oss-fuzz:32587
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/389636
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-29 14:35:09 +00:00
John Stiles
2febb5b423 Add SkSL test for vector-scalar math.
We had constant-folding tests for vector-scalar arithmetic, but didn't
have an equivalent SkSL unit test for vector-scalar arithmetic that
actually needs to be computed at runtime.

This exposes two SPIR-V bugs: one was previously known, but the other
is a new discovery.

Change-Id: I28737128f20b445797c6c29872335d05f94cc95c
Bug: skia:11267, skia:11788
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388739
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-25 23:30:34 +00:00
John Stiles
0c9d888748 Run SkSL inliner tests as part of dm.
Previously, these tests were never actually executed, only read during
code review. They are now properly tested for correctness whenever dm
is run. Non-ES2 compliant statements (do/while/switch) are unfortunately
excluded here, as they are not compatible with Runtime Effects yet.

Change-Id: I965c782baad6f8dd3961a400ae791fb2c1f844d3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/389296
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-25 22:58:54 +00:00
John Stiles
85749c0b22 Add caps bit for RewriteMatrixVectorMultiply.
On ARM GPUs, the Vulkan driver does not honor relaxed precision when
evaluating SpvOpMatrixTimesVector. This leads to reduced performance
(compared to GLSL, where mediump matrices and floats do evaluate all
intermediate values at mediump).

This caps bit will be enabled on ARM GPUs and, in a followup CL, will
be used to toggle a workaround where `m*v` is rewritten as the sum of
(m[0]*v[0] + m[1]*v[1] + ... + m[N]*v[N]).

Change-Id: I310fa73639b6498552c9672e76860f2eded15d0a
Bug: skia:11769
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388459
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-23 22:40:02 +00:00
Brian Osman
d1f3b97a64 Remove sk_SampleMask support from SkSL
Change-Id: I22837a4921238749664217e595d24d196503534d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/388096
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-03-23 14:37:28 +00:00
John Stiles
1b843bdcb7 Fix up outdated tests.
Removed error tests which no longer test anything:
- UseWithoutInitialize...: we no longer track variable use-before-init.
- InlineDivideByZero: we no longer constant-fold the result of an
  inlined function call into its parent statement.
- Unreachable: we no longer report unreachable statements.

And fixed some minor test-case issues:
- StaticSwitchConditionalBreak: we still check this, but the function
  was being dead-stripped before this check could run. Renamed to main.
- OssFuzzXxxxx: these cases no longer report errors, but they are still
  valuable as regression tests; moved to `shared/`.

Change-Id: Iade3cff821dc998cacfd02f62d3ac4625e48904c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387820
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-03-22 21:11:47 +00:00
John Stiles
95eadd32c1 Rename 'unpremul_float' to 'unpremul.'
Now that name mangling is implemented, we don't need to worry about name
collisions when high-precision types are disabled.

Change-Id: Ic0def3e629deeb804745ff683826946947c898e3
Bug: skia:10851
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387758
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-22 17:34:16 +00:00
John Stiles
ece1d794b9 Mangle function names in GLSL.
This will be implemented in Metal and SPIR-V in followup CLs.

Change-Id: I397b4db40b15dd54cf1d8a17f414c3fe184b48d2
Bug: skia:10851
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/387638
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-22 17:18:26 +00:00
John Stiles
e67bd1371e Migrate VarDeclaration conversion out of IRGenerator.
Change-Id: If5fb4f99d327bb429f60e8d6c526720dd02b0928
Bug: skia:11342
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/386800
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-03-22 14:25:26 +00:00
John Stiles
bff24abab8 Disallow inlining a function with out-parameters.
It is difficult to do this both efficiently and correctly while honoring
GLSL semantics (which require the lvalues to be kept distinct, even when
they point to the same variable). We could make it work by making copies
of every out parameter in each direction (going in for inouts, and
coming out for outs and inouts).

However, this could be self-defeating if it makes it harder for the
driver to track variable lifetimes. Simply opting out of inlining these
functions entirely seems like the best tradeoff; let the driver optimize
them if it can, and we can enjoy reduced complexity in the SkSL inliner.

Change-Id: I62f7b4550cc181cfe789e4f2ff4e408ba1baf9cb
Bug: skia:11326
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370257
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-17 18:04:00 +00:00
Ethan Nicholas
e0707b7075 No longer passing the results of OpAccessChain to function calls
It turns out it is not legal to pass the results of OpAccessChain as a
function argument, for... reasons. This CL switches us over to passing
the argument via a temp variable instead.

Bug: skia:11748
Change-Id: Ib5e86c1d000655ebd7bb62ceea6a27b823808645
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385936
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2021-03-17 16:37:00 +00:00
John Stiles
dc20847579 Disallow inlining functions containing early returns.
This allows us to remove 100 LOC from the inliner and is very unlikely
to affect any existing benchmark. We don't have any evidence to support
the idea that a one-iteration `for` loop with `continue`-based exits
will be any faster than a standard function call on any existing GPU.
Our fragment processors are generally written to avoid early returns,
in large part to avoid hitting this path.

This drastically impacts BlendEnum.sksl (which can no longer flatten out
a switch over every blend function in SkSL) but is otherwise a wash.

See: http://go/optimization-in-sksl-inliner suggestion 4(a)

Change-Id: I1f9c27bcd7a8de46cc4e8d0b9768d75957cf1c50
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385377
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-03-17 16:29:00 +00:00
John Stiles
2810beed23 Improve do-while test in CanExitWithoutReturningValue.
This put the coverage for do-while loops on par with for loops.

Change-Id: I53e0d733edd02a6a139792a8d74c68116453e5ff
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385500
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-17 14:50:56 +00:00
John Stiles
f10eff363b Fix misdetection of dead global variables.
A global variable should be considered "dead" if it's never written and
never read. The previous code checked if it was never written OR never
read, which is not the same.

This would generate GLSL/Metal that didn't compile. In SPIR-V, it would
SkASSERT, then crash, during codegen. The fuzzer was able to detect the
SPIR-V issue, but it was wrong in all three cases.

Change-Id: Id59a2499eb5baa3839b93826bfbc24191bfd490b
Bug: oss-fuzz:32005
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385280
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-16 16:02:03 +00:00
Brian Osman
8c595fed7c Change sksl tests to avoid SPIR-V validation errors
'in' variables without locations aren't allowed. Use uniforms instead.

Bug: skia:11738
Change-Id: Ic066106deb7409cff154b4be7cfb3e03a7025c7d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/385000
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-03-16 13:39:53 +00:00
Brian Osman
fc4b9919d3 Force global initializers to be constant expressions
Prevents us from accepting code that can't be correctly transformed to
GLSL, like:

  uniform float x;
  float y = x;

(Previously, writing code like that in a runtime effect would
effectively produce the exact same code all the way through to GLSL, and
the driver would fail to compile it).

Bug: skia:11336
Change-Id: Iaa797587c4a4a7289ed59ce2736cf0bf0fc5bca3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/384698
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-03-15 16:54:05 +00:00
John Stiles
97d8d7fce0 Remove obsolete TODO.
The referenced bug is closed, and the compiler does correctly emit an
error here.

Change-Id: I824f7819a1e077163f528ac503f3743aab5e58a1
Bug: skia:11322
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/384697
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-03-15 14:43:25 +00:00
Ethan Nicholas
2f4652f309 Revert "Fixed a number of spots where we should have been using RelaxedPrecision"
This reverts commit a04692f69e.

Reason for revert: Angry Vulkan bots.

Original change's description:
> Fixed a number of spots where we should have been using RelaxedPrecision
>
> Our SPIR-V output was missing many RelaxedPrecision decorations, which
> was presumably impacting performance.
>
> Change-Id: Iee32d4a42f37af167fe0e45f3db94c2142129695
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/384178
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

TBR=egdaniel@google.com,brianosman@google.com,ethannicholas@google.com,johnstiles@google.com

Change-Id: If4fe945cb363c9b61b5a4abfde649a437689d2eb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/384217
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2021-03-12 18:48:57 +00:00
Ethan Nicholas
a04692f69e Fixed a number of spots where we should have been using RelaxedPrecision
Our SPIR-V output was missing many RelaxedPrecision decorations, which
was presumably impacting performance.

Change-Id: Iee32d4a42f37af167fe0e45f3db94c2142129695
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/384178
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2021-03-12 18:00:56 +00:00
John Stiles
f3a28db703 Eliminate control-flow analysis.
We no longer derive a performance benefit from this pass in practice,
and it is a very expensive compilation step. It is also prone to fuzz-
related errors.

Doc: http://go/optimization-in-sksl

Change-Id: Ief08ffac659a8fe7fe92c92b9a5da14c9f713bc2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381261
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-11 13:24:54 +00:00
John Stiles
0dd1a77e12 Add noinline keyword to SkSL.
As you might expect, a function tagged with `noinline` will never be
considered as a candidate for inlining.

Change-Id: Ia098f8974e6de251d78bb2a76cd71db8a86bc19c
Bug: skia:11362
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/382337
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-03-10 15:39:48 +00:00
Brian Osman
86e85537fe Test that we propagate 'const' to the GPU backend of runtime effects
Currently, only one of three uses (local variables) does this correctly.

Bug: skia:11716
Change-Id: Iad11e8e5998fcc7caee4d438e0558c5d4e2b1821
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/382277
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-03-09 23:26:00 +00:00
John Stiles
51d33982ad Add Convert/Make factory functions to IndexExpression.
Change-Id: I7a7874e58bf53978afce8a41b26092406b6490ed
Bug: skia:11342
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/380360
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-08 15:55:59 +00:00
John Stiles
6fb520fcd5 Improve optimization of prefix expressions at IR time.
- Values from constant variables are folded in when it helps, e.g.:

    const bool SHINY = true;
    const float SHININESS = 2;
    if (!SHINY) {  // <-- optimizes directly to `false`
       param = -SHININESS; // <-- optimizes to `-2`

- Doubled-up logical-not and negation are stripped:

    y = -(-x); // <-- optimizes to `y = x;`
    b = !!a; // <-- optimizes to `b = a;`

Removal of doubled-up negation and logical-not was actually never
implemented in the constant-propagation phase; I just noticed it while
I was here and thinking about it.

Change-Id: Ie28bb9b5af91376f03d926e26e37f4a131bbf550
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379298
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-05 21:41:55 +00:00
John Stiles
28054added Optimize ternary tests that check a const variable.
This enables the ternary to be optimized away in code like:
   const bool SHINY = true;
   color = SHINY ? add_shine(x) : x; // to --> `color = add_shine(x);`

Without constant propagation.

Also, I added a unit test for ternary expression simplification; I
wasn't able to find an existing one.

When the optimization flag is disabled, this CL actually removes the
optimization of `true ? x : y` --> `x` entirely; previously, this
substitution would be made regardless of optimization settings.

Change-Id: I93a8b9d4027902d35f8a19cfd6417170b209d056
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379297
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-03-05 21:41:05 +00:00
John Stiles
b3dcbb12ef Detect functions that fail to return a value, without using CFG.
This check now runs at function finalization time, before constant
propagation has occurred; this affected the "DeadIfStatement" test.

Our detection isn't smart enough to realize that a loop will run zero
times, so it treats `for` and `while` loops as always running at least
once. This isn't strictly correct, but it actually mirrors how the CFG
implementation works anyway. The only downside is that we would not flag
code like `for (i=0; i<0; ++i) { return x; }` as an error.

Change-Id: I5e43a6ee3a3993045559f0fb0646d36112543a94
Bug: skia:11377
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379056
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-03-04 22:47:05 +00:00
John Stiles
2b6ec98a82 Disallow unscoped for blocks which declare a variable.
This should be legal, and we support this, but some versions of Android
do not: http://screen/3bkQewHF3xUMn5v There's no point in allowing
these shaders to exist; they can't compile on real-world clients, and
these vardecls are borderline meaningless (as the variables being
declared aren't reachable by any other statements).

Change-Id: Ie1351933c90caee9124eeab8983364ec030b2653
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379584
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-04 17:04:40 +00:00
John Stiles
4633c9149b # Enter a description of the change.
Reland "Migrate if-statement simplifyStatement logic to IfStatement::Make."

This reverts commit 7e685f0377.

Reason for revert: fixed SkSLBench perf test

Original change's description:
> Revert "Migrate if-statement simplifyStatement logic to IfStatement::Make."
>
> This reverts commit e4da7b672f.
>
> Reason for revert: breaks SkSLBench perf test
>
> Original change's description:
> > Migrate if-statement simplifyStatement logic to IfStatement::Make.
> >
> > This performs essentially the same simplifications as before, just at
> > a different phase of compilation.
> >
> > Change-Id: Ia88df6857d4089962505cd1281798fda74fd0b02
> > Bug: skia:11343, skia:11319
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376177
> > Commit-Queue: John Stiles <johnstiles@google.com>
> > Auto-Submit: John Stiles <johnstiles@google.com>
> > Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
>
> TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
>
> Change-Id: I0051188ffe69426904066eb60a932435efdc2af8
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: skia:11343
> Bug: skia:11319
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379062
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: John Stiles <johnstiles@google.com>

Bug: skia:11343
Bug: skia:11319
Change-Id: I74cc3295004133e9fdcf16e388106eb83603f526
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379063
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-03 22:21:36 +00:00
John Stiles
7e685f0377 Revert "Migrate if-statement simplifyStatement logic to IfStatement::Make."
This reverts commit e4da7b672f.

Reason for revert: breaks SkSLBench perf test

Original change's description:
> Migrate if-statement simplifyStatement logic to IfStatement::Make.
>
> This performs essentially the same simplifications as before, just at
> a different phase of compilation.
>
> Change-Id: Ia88df6857d4089962505cd1281798fda74fd0b02
> Bug: skia:11343, skia:11319
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376177
> Commit-Queue: John Stiles <johnstiles@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Ethan Nicholas <ethannicholas@google.com>

TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com

Change-Id: I0051188ffe69426904066eb60a932435efdc2af8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:11343
Bug: skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379062
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-03 20:50:37 +00:00
John Stiles
e4da7b672f Migrate if-statement simplifyStatement logic to IfStatement::Make.
This performs essentially the same simplifications as before, just at
a different phase of compilation.

Change-Id: Ia88df6857d4089962505cd1281798fda74fd0b02
Bug: skia:11343, skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376177
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-03-03 18:12:35 +00:00
John Stiles
2dda50dd50 Add return-value check to the function finalizer.
Rather than have the inliner own this responsibility, the function
finalizer now detects if a function is supposed to return a value but
never actually does. This will allow us to detect this error case even
if the inliner is disabled. The inliner should no longer encounter
functions that claim to return a value but don't, so it will now assert
if one is encountered. (The inliner still has the logic to handle this
case gracefully, just in case.)

The check is currently very simple and doesn't analyze the structure of
the function, so it won't report cases where some paths return a value
and others don't, e.g. this will pass the test:

    int func() { if (something()) return 123; }

(This is good enough to resolve the inliner issue, though, as it only
occurred in functions with no value-returns at all.)

Change-Id: I21f13daffe66c8f2e72932b320ee268ba9207bfa
Bug: oss-fuzz:31469, oss-fuzz:31525, skia:11377
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/377196
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
2021-03-03 16:29:22 +00:00
Brian Osman
dc4f8cd7ea Add early_fragment_tests layout qualifier to SkSL
Bug: skia:11356
Change-Id: I16322e6396dc7e7c8c50ba1d39e07311cf3bd346
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376116
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-03-02 16:45:03 +00:00
John Stiles
0c2d14a1b9 Fix fuzzer-discovered error with inlining.
In http://review.skia.org/375776, an optimization was added to the
Inliner, causing it to skip generation of unnecessary temporary
variables. The fuzzer immediately discovered a flaw in this logic: the
"unnecessary" variable was actually used in the rare case that a
function failed to actually return a value. The inliner didn't detect
this case. Of course, this isn't a valid program either, so now we
report the error and cleanly fail.

Change-Id: I1f201cfd33f45cace3be93765a4e214e43a46e69
Bug: oss-fuzz:31469, oss-fuzz:31525
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/377101
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-03-01 20:06:50 +00:00
Brian Osman
a654faaf7f Add permittedLayoutFlags to checkModifiers
For now, just use this to prevent *any* layout qualifiers from appearing
on functions, or their parameters.

Bug: skia:11301
Change-Id: I05d8118c7121048c6ef49695a54e3714a8f8687e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376796
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-02-26 18:38:31 +00:00
Brian Osman
7b361499c9 Align SkSL const rules more closely with GLSL
This adds Analysis::IsConstantExpression, to determine if an expression
is a constant-expression. It now expands to cover 'const' local and
global variables, because we also enforce that the initializer on those
variables is - in turn - a constant expression.

This fixes 10837 - previously you could initialize a const variable with
a non-constant expression, and we'd emit GLSL that contained that same
pattern, which would fail to compile at the driver level. That should
not be possible any longer.

Bug: skia:10679
Bug: skia:10837
Change-Id: I517820ef4da57fff45768c0b04c55aebc18d3272
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375856
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-26 17:44:11 +00:00
John Stiles
bb8542f086 Fix fuzzer-discovered error with ~ prefix on literals.
The expression `~123` was making a PrefixExpression of type $intLiteral.
It should be converted to type `int` when the ~ prefix is applied.

This change also changes the output from oss-fuzz:27614. Both programs
are essentially nonsense expressions with no real behavior, so this is
fine.

Change-Id: I586be149ce95136fabee72fdd3473814d54948cf
Bug: oss-fuzz:31410
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376620
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-02-26 17:30:26 +00:00
Brian Osman
029851d951 Remove fragmentProcessor field access
Change-Id: Iafeb13812851271a5262730e9c0642d4469c273f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375020
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-24 21:33:36 +00:00
Brian Osman
a77ed8b382 Add flags for all layout qualifiers, check for duplicates
Now, even if a qualifier has a default value, we will know that it
appeared in the text. We can use that to check for redundant qualifiers
(as is being done here), and in the IR generator to prevent any use of
certain qualifiers, depending on context. (eg, runtime effects, wrong
shader stage, on a parameter declaration, etc.)

Bug: skia:11301
Change-Id: I2cd6ad35c2b4c4d6f87ade97e80aea84dc16ee4b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374616
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-02-24 16:22:26 +00:00
John Stiles
642cde289d Optimize @switch statements in SwitchStatement::Make.
At IR generation time, this CL limits our optimizations to only
@switch statements. A regular switch statement will only be optimized
during the optimization phase even if the switch-value is a known
compile-time constant. This is done to avoid upsetting our reachability
analysis.

Most of this CL is moving existing logic from SkSLCompiler into
SkSLAnalysis and SkSLSwitchStatement. Although the diffs look large, the
actual changes are very small.

Change-Id: I90920f41bc386dfa7a980ae7510f6681231a5120
Bug: skia:11340, skia:11342, skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372679
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-02-23 21:36:04 +00:00
Brian Osman
4a015c5092 Require initializers on const variable declarations
Bug: skia:10837
Change-Id: I33da2eb1e723ed04ab62d65c21e54306dd362bed
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372677
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-23 20:55:01 +00:00
Brian Osman
4882e9a43d Remove specific blend mode layout qualifiers
These were unused - we always enable the advanced blend equation
extension using "blend_support_all_equations" (if enabling the
extension is required at all).

Change-Id: I95fd6483ec54dfaf983290de95629fe0e86c22e8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/373877
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
2021-02-23 15:45:55 +00:00
John Stiles
2b3d1f2086 Remove constant propagation from static-switch test.
Constant propagation might be going away, but static-switches are likely
here to stay. Avoid conflating the two in this test.

Change-Id: If4b6c99c85f124d3bbc20da858693f09f5e4fd59
Bug: skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374117
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-02-23 15:39:05 +00:00
John Stiles
04ca41acf3 Fix switch optimization pass.
The optimizer now properly recognizes all types of exits from a switch
statement. Break, continue and return are all potential exits and need
to be considered when determining the exit path from the switch.

Previously, dead code elimination was hiding the effects of this bug
from us, but it meant that an optimized switch had the potential to
generate lots of worthless IR nodes which then needed to be detected and
eliminated by the CFG. In particular, this affected the enum form of
blend, causing a catastrophic amount of extra work to be done.

Change-Id: If857e38cadfc016884624ea4db25a273ad3dce5b
Bug: skia:11352
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372958
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2021-02-23 15:38:24 +00:00
Brian Osman
ffee4766fa SkSL: Allow 'const' on function parameters
Change-Id: I672345116e3b5538c0f7e8c5f2f74aa56bb81e6d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372676
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2021-02-22 21:40:26 +00:00
John Stiles
66c53b9428 Demonstrate a bug with inlined static switches.
When we detect a static switch, the optimizer finds the matching switch-
case and eliminates all the other switch-cases. It handles case
fall-through by scanning forward and looking for an unconditional break.

However, the inliner has an interesting quirk--it can replace `return`
statements inside of a switch with `continue` statements, since the body
of the inlined function has been wrapped with a for-loop to allow for
early exits. The optimizer does not recognize these continue statements
as exits from the switch (although they certainly qualify), so it
treats continues as fallen-through and keeps emitting switch-cases.

The dead-code elimination pass was actually doing us a favor here and
eliminating the excess code later. A flag was added to disable DCE in
order to reveal the problem in a test.

Change-Id: I8ff19fde5e32d0ab73d7c5411da40cb953a446f5
Bug: skia:11352
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372956
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-02-22 15:05:58 +00:00
John Stiles
463fad21ba Add test for duplicate default switch-case.
Surprisingly, this error is actually caught by our parser, which
interprets the default label in a unique way. From the parser comments:

  "Requiring default: to be last (in defiance of C and GLSL) was a
   deliberate decision. Other parts of the compiler may rely upon this
   assumption."

The comment is true--we don't check for duplicate default switch-case
labels anywhere else in the code, just here in the parser.

We rely on this, so we should have a test for it.

Change-Id: I6df5c565aca4d4b8565b96638dce9504efc39ccc
Bug: skia:11340
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372617
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
2021-02-19 20:31:50 +00:00
Brian Osman
58ee89879f Remove "buffer" modifier from SkSL
Change-Id: I4df18946cdb3d9f1f7833461f913f2df94696821
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372197
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-02-18 21:48:05 +00:00
Brian Osman
9ca38ff4b4 Remove GLSL memory qualifiers from SkSL
These were all unused, and only implemented on one backend.

Change-Id: Ibd2fcef1a971e6c1bd9da0784c5d852a60708484
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372117
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
2021-02-18 19:57:05 +00:00