[MooreToCore] Support pows and powu op #7899
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Hi @fabianschuiki , I have incorporated the advice from you and @maerhart . Please let me know if there are any issues with my code or the test cases. Thank you so much for taking the time to review this. I really appreciate your feedback! :) |
| auto intType = cast<IntType>(op.getRhs().getType()); | ||
| if (auto baseOp = op.getLhs().getDefiningOp<ConstantOp>()) { | ||
| if (baseOp.getValue() == 2) { | ||
| Value constOne = rewriter.create<ConstantOp>(loc, intType, 1); | ||
| rewriter.replaceOpWithNewOp<ShlOp>(op, constOne, op.getRhs()); | ||
| return success(); | ||
| } | ||
| } |
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This would be fantastic to have as a canonicalization in the Moore dialect! Could you move this into the canonicalizer of moore::PowUOp? (You might have to add a let hasCanonicalizeMethod = 1 to the PowUOp definition in the MooreOps.td file.)
| auto intType = cast<IntType>(op.getRhs().getType()); | ||
| if (auto baseOp = op.getLhs().getDefiningOp<ConstantOp>()) { | ||
| if (baseOp.getValue() == 2) { | ||
| Value constOne = rewriter.create<ConstantOp>(loc, intType, 1); | ||
| Value constZero = rewriter.create<ConstantOp>(loc, intType, 0); | ||
| Value shift = rewriter.create<ShlOp>(loc, constOne, op.getRhs()); | ||
| Value isNegative = rewriter.create<SltOp>(loc, op.getRhs(), constZero); | ||
| auto condOp = rewriter.replaceOpWithNewOp<ConditionalOp>( | ||
| op, op.getLhs().getType(), isNegative); | ||
| Block *thenBlock = rewriter.createBlock(&condOp.getTrueRegion()); | ||
| rewriter.setInsertionPointToStart(thenBlock); | ||
| rewriter.create<YieldOp>(loc, constZero); | ||
| Block *elseBlock = rewriter.createBlock(&condOp.getFalseRegion()); | ||
| rewriter.setInsertionPointToStart(elseBlock); | ||
| rewriter.create<YieldOp>(loc, shift); | ||
| return success(); | ||
| } | ||
| } |
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This would be fantastic to have as a canonicalization in the Moore dialect! Could you move this into the canonicalizer of moore::PowSOp? (You might have to add a let hasCanonicalizeMethod = 1 to the PowSOp definition in the MooreOps.td file.)
| // if the exponent is negative, lhsVal = 1 / lhs, upperBound = -rhs | ||
| Value invLhs = rewriter.create<comb::DivUOp>( | ||
| loc, rewriter.create<hw::ConstantOp>(loc, resultType, 1), lhsVal); | ||
| Value negRhs = rewriter.create<comb::SubOp>(loc, constZero, rhsVal); | ||
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| lhsVal = rewriter.create<comb::MuxOp>(loc, isNegative, invLhs, lhsVal); | ||
| Value upperBound = | ||
| rewriter.create<comb::MuxOp>(loc, isNegative, negRhs, rhsVal); |
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If the exponent is negative, can this ever produce anything besides 0? Since these are integers, I'd assume 1 / lhs to always return 0, since there are no fractional numbers. We'll have to figure out a way to represent real numbers, but you could check if the PowSOp type is a moore::IntType, and only implement integers for now. (We don't really have a lowering for SystemVerilog's real type yet. That would be cool to add at some point -- but we'd probably have to map that to the arith MLIR dialect and MLIR's standard floating-point type.)
Fixes #7626