document compiler procs regarding & (#20257)

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ringabout 2022-08-22 16:11:43 +08:00 • committed by GitHub
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3 changed files with 8 additions and 2 deletions

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@ -1197,7 +1197,7 @@ proc strLoc(p: BProc; d: TLoc): Rope =
proc genStrConcat(p: BProc, e: PNode, d: var TLoc) = proc genStrConcat(p: BProc, e: PNode, d: var TLoc) =
# <Nim code> # <Nim code>
# s = 'Hello ' & name & ', how do you feel?' & 'z' # s = "Hello " & name & ", how do you feel?" & 'z'
# #
# <generated C code> # <generated C code>
# { # {
@ -1240,7 +1240,7 @@ proc genStrConcat(p: BProc, e: PNode, d: var TLoc) =
proc genStrAppend(p: BProc, e: PNode, d: var TLoc) = proc genStrAppend(p: BProc, e: PNode, d: var TLoc) =
# <Nim code> # <Nim code>
# s &= 'Hello ' & name & ', how do you feel?' & 'z' # s &= "Hello " & name & ", how do you feel?" & 'z'
# // BUG: what if s is on the left side too? # // BUG: what if s is on the left side too?
# <generated C code> # <generated C code>
# { # {

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@ -8,6 +8,7 @@
# #
# This include implements the high level optimization pass. # This include implements the high level optimization pass.
# included from sem.nim
when defined(nimPreviewSlimSystem): when defined(nimPreviewSlimSystem):
import std/assertions import std/assertions

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@ -806,6 +806,8 @@ proc getMergeOp(n: PNode): PSym =
else: discard else: discard
proc flattenTreeAux(d, a: PNode, op: PSym) = proc flattenTreeAux(d, a: PNode, op: PSym) =
## Optimizes away the `&` calls in the children nodes and
## lifts the leaf nodes to the same level as `op2`.
let op2 = getMergeOp(a) let op2 = getMergeOp(a)
if op2 != nil and if op2 != nil and
(op2.id == op.id or op.magic != mNone and op2.magic == op.magic): (op2.id == op.id or op.magic != mNone and op2.magic == op.magic):
@ -898,6 +900,9 @@ proc transformExceptBranch(c: PTransf, n: PNode): PNode =
result = transformSons(c, n) result = transformSons(c, n)
proc commonOptimizations*(g: ModuleGraph; idgen: IdGenerator; c: PSym, n: PNode): PNode = proc commonOptimizations*(g: ModuleGraph; idgen: IdGenerator; c: PSym, n: PNode): PNode =
## Merges adjacent constant expressions of the children of the `&` call into
## a single constant expression. It also inlines constant expressions which are not
## complex.
result = n result = n
for i in 0..<n.safeLen: for i in 0..<n.safeLen:
result[i] = commonOptimizations(g, idgen, c, n[i]) result[i] = commonOptimizations(g, idgen, c, n[i])