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Oh, no. I should have been more clear. The patch was not rejected, just lost in the daily shuffle. I already have my employer's approval to send this upstream, so I will prepare a patch against trunk this morning. > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > > Parts of my patch did make it into trunk about a year after, but others > > did not.

On Monday, July 30, 2012 12:16 AM, Cameron McInally wrote: > Hey Andy, > > I proposed a similar patch to LLVM (left circular shift) around 10/2011. > Parts of my patch did make it into trunk about a year after, but others > did not. > > At that time, my solution was to add a binary operator to the IRBuilder, > since LCS fits in nicely with the other shift operators. But,

...sLeftShift = I.getOpcode() == Instruction::Shl; - // See if we can propagate this shift into the input, this covers the trivial // cast of lshr(shl(x,c1),c2) as well as other more complex cases. if (I.getOpcode() != Instruction::AShr && @@ -527,7 +531,12 @@ BinaryOperator *ShiftOp = dyn_cast<BinaryOperator>(Op0); if (ShiftOp && !ShiftOp->isShift()) ShiftOp = 0; - + + if (ShiftOp && ShiftOp->getOpcode() == Instruction::CShl) { + // Don't combine circular shifts for now. + return 0; + } + if (ShiftOp && isa<Cons...