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| author | Reimer Behrends <behrends@gmail.com> | 2015-11-11 14:19:09 +0100 |
|---|---|---|
| committer | Reimer Behrends <behrends@gmail.com> | 2015-11-11 14:19:09 +0100 |
| commit | 67e62302b4791f68830c32e63b2cee0842e6882f (patch) | |
| tree | d910cba03320f0903b4c306647e58d7556e39279 | |
| parent | f9ad735e55d45d6a3ed7e9e7da7abd31065f99ac (diff) | |
| download | Nim-67e62302b4791f68830c32e63b2cee0842e6882f.tar.gz | |
Avoid signed shifts and bit operations for sets.
Set operations used "1<<n" style shifts, which led to undefined behavior if the signed shift overflowed. Similarly, the right-hand side of the operator sometimes used a mix of signed and unsigned integers that were combined with "&". This patch attempts to provide a consistent implementation that uses unsigned integers everywhere.
| -rw-r--r-- | compiler/ccgexprs.nim | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim index c9ff9d4f0..b595fa60c 100644 --- a/compiler/ccgexprs.nim +++ b/compiler/ccgexprs.nim @@ -1415,11 +1415,11 @@ proc binaryExprIn(p: BProc, e: PNode, a, b, d: var TLoc, frmt: string) = proc genInExprAux(p: BProc, e: PNode, a, b, d: var TLoc) = case int(getSize(skipTypes(e.sons[1].typ, abstractVar))) - of 1: binaryExprIn(p, e, a, b, d, "(($1 &(1<<(($2)&7)))!=0)") - of 2: binaryExprIn(p, e, a, b, d, "(($1 &(1<<(($2)&15)))!=0)") - of 4: binaryExprIn(p, e, a, b, d, "(($1 &(1<<(($2)&31)))!=0)") - of 8: binaryExprIn(p, e, a, b, d, "(($1 &(IL64(1)<<(($2)&IL64(63))))!=0)") - else: binaryExprIn(p, e, a, b, d, "(($1[$2/8] &(1<<($2%8)))!=0)") + of 1: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&7U)))!=0)") + of 2: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&15U)))!=0)") + of 4: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&31U)))!=0)") + of 8: binaryExprIn(p, e, a, b, d, "(($1 &((NU64)1<<((NU)($2)&63U)))!=0)") + else: binaryExprIn(p, e, a, b, d, "(($1[(NU)($2)>>3] &(1U<<((NU)($2)&7U)))!=0)") proc binaryStmtInExcl(p: BProc, e: PNode, d: var TLoc, frmt: string) = var a, b: TLoc @@ -1500,8 +1500,8 @@ proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) = else: internalError(e.info, "genSetOp()") else: case op - of mIncl: binaryStmtInExcl(p, e, d, "$1[$2/8] |=(1<<($2%8));$n") - of mExcl: binaryStmtInExcl(p, e, d, "$1[$2/8] &= ~(1<<($2%8));$n") + of mIncl: binaryStmtInExcl(p, e, d, "$1[(NU)($2)>>3] |=(1U<<($2&7U));$n") + of mExcl: binaryStmtInExcl(p, e, d, "$1[(NU)($2)>>3]] &= ~(1U<<($2&7U));$n") of mCard: unaryExprChar(p, e, d, "#cardSet($1, " & $size & ')') of mLtSet, mLeSet: getTemp(p, getSysType(tyInt), i) # our counter @@ -1788,11 +1788,11 @@ proc genSetConstr(p: BProc, e: PNode, d: var TLoc) = initLocExpr(p, e.sons[i].sons[0], a) initLocExpr(p, e.sons[i].sons[1], b) lineF(p, cpsStmts, "for ($1 = $3; $1 <= $4; $1++) $n" & - "$2[$1/8] |=(1<<($1%8));$n", [rdLoc(idx), rdLoc(d), + "$2[(NU)($1)>>3] |=(1U<<((NU)($1)&7U));$n", [rdLoc(idx), rdLoc(d), rdSetElemLoc(a, e.typ), rdSetElemLoc(b, e.typ)]) else: initLocExpr(p, e.sons[i], a) - lineF(p, cpsStmts, "$1[$2/8] |=(1<<($2%8));$n", + lineF(p, cpsStmts, "$1[(NU)($2)>>3] |=(1U<<((NU)($2)&7U));$n", [rdLoc(d), rdSetElemLoc(a, e.typ)]) else: # small set |