jyapayne/Nim
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Openmp parallel iterator improvements (#9493)

Browse source 
* More flexibility in OpenMP pragma
* Use static to constrain to compile-time annotation string
* Update changelog with OpenMP change
This commit is contained in:
Mamy Ratsimbazafy 2018-10-25 18:09:35 +02:00 • committed by Andreas Rumpf
commit 5b97762787
4 changed files with 13 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

6
changelog.md
View file

@ -11,6 +11,12 @@
use `editdistance.editDistance` or `editdistance.editDistanceAscii` use `editdistance.editDistance` or `editdistance.editDistanceAscii`
instead. instead.
- The OpenMP parallel iterator \``||`\` now supports any `#pragma omp directives`
and not just `#pragma omp parallel for`. See [OpenMP documentation](https://www.openmp.org/wp-content/uploads/OpenMP-4.5-1115-CPP-web.pdf).
The default annotation is `parallel for`, if you used OpenMP without annotation
the change is transparent, if you used annotations you will have to prefix
your previous annotations with `parallel for`.
#### Breaking changes in the standard library #### Breaking changes in the standard library

2
compiler/ccgstmts.nim
View file

@ -557,7 +557,7 @@ proc genParForStmt(p: BProc, t: PNode) =
initLocExpr(p, call.sons[1], rangeA) initLocExpr(p, call.sons[1], rangeA)
initLocExpr(p, call.sons[2], rangeB) initLocExpr(p, call.sons[2], rangeB)
lineF(p, cpsStmts, "#pragma omp parallel for $4$n" & lineF(p, cpsStmts, "#pragma omp $4$n" &
"for ($1 = $2; $1 <= $3; ++$1)", "for ($1 = $2; $1 <= $3; ++$1)",
[forLoopVar.loc.rdLoc, [forLoopVar.loc.rdLoc,
rangeA.rdLoc, rangeB.rdLoc, rangeA.rdLoc, rangeB.rdLoc,

5
compiler/semexprs.nim
View file

@ -2041,11 +2041,6 @@ proc semMagic(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
result = c.graph.emptyNode result = c.graph.emptyNode
of mOmpParFor: of mOmpParFor:
checkMinSonsLen(n, 3, c.config) checkMinSonsLen(n, 3, c.config)
if n.sonsLen == 4:
let annotationStr = getConstExpr(c.module, semExpr(c, n[^1]), c.graph)
if annotationStr == nil or annotationStr.kind notin nkStrKinds:
localError(c.config, result[^1].info,
"The annotation string for `||` must be known at compile time")
result = semDirectOp(c, n, flags) result = semDirectOp(c, n, flags)
else: else:
result = semDirectOp(c, n, flags) result = semDirectOp(c, n, flags)

8
lib/system.nim
View file

@ -2186,10 +2186,14 @@ else:
inc(res) inc(res)
iterator `||`*[S, T](a: S, b: T, annotation=""): T {. iterator `||`*[S, T](a: S, b: T, annotation: static string = "parallel for"): T {.
inline, magic: "OmpParFor", sideEffect.} = inline, magic: "OmpParFor", sideEffect.} =
## parallel loop iterator. Same as `..` but the loop may run in parallel. ## OpenMP parallel loop iterator. Same as `..` but the loop may run in parallel.
## `annotation` is an additional annotation for the code generator to use. ## `annotation` is an additional annotation for the code generator to use.
## The default annotation is `parallel for`.
## Please refer to the `OpenMP Syntax Reference<https://www.openmp.org/wp-content/uploads/OpenMP-4.5-1115-CPP-web.pdf>`_
## for further information.
##
## Note that the compiler maps that to ## Note that the compiler maps that to
## the ``#pragma omp parallel for`` construct of `OpenMP`:idx: and as ## the ``#pragma omp parallel for`` construct of `OpenMP`:idx: and as
## such isn't aware of the parallelism in your code! Be careful! Later ## such isn't aware of the parallelism in your code! Be careful! Later