luke/verilator
1
0
Fork 0
mirror of https://github.com/verilator/verilator.git synced 2026-10-07 10:33:13 +02:00
Code Issues Packages Projects Releases Wiki Activity

Fix replaceMulShift optimization (#2413)

Browse Source
This commit is contained in:
Conor McCullough
2020-06-11 07:42:25 -04:00
committed by Wilson Snyder
parent 262ed9c03a
commit f40f0464e2
4 changed files with 78 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/V3Const.cpp
+2 -1
View File
@@ -588,6 +588,7 @@ private:
}
return false;
}
bool operandsSameSize(AstNode* lhsp, AstNode* rhsp) { return lhsp->width() == rhsp->width(); }
//----------------------------------------
// Constant Replacement functions.
@@ -2322,7 +2323,7 @@ private:
TREEOP ("AstMulS {$lhsp.isOne, $rhsp}", "replaceWRhs(nodep)");
TREEOP ("AstDiv {$lhsp, $rhsp.isOne}", "replaceWLhs(nodep)");
TREEOP ("AstDivS {$lhsp, $rhsp.isOne}", "replaceWLhs(nodep)");
TREEOP ("AstMul {operandIsPowTwo($lhsp), $rhsp}", "replaceMulShift(nodep)"); // a*2^n -> a<<n
TREEOP ("AstMul {operandIsPowTwo($lhsp), operandsSameSize($lhsp,,$rhsp)}", "replaceMulShift(nodep)"); // a*2^n -> a<<n
TREEOP ("AstDiv {$lhsp, operandIsPowTwo($rhsp)}", "replaceDivShift(nodep)"); // a/2^n -> a>>n
TREEOP ("AstModDiv{$lhsp, operandIsPowTwo($rhsp)}", "replaceModAnd(nodep)"); // a % 2^n -> a&(2^n-1)
TREEOP ("AstPow {operandIsTwo($lhsp), $rhsp}", "replacePowShift(nodep)"); // 2**a == 1<<a