[llvm] [GlobalISel] Combine (X >> C) << C to X & ((-1 >> C) << C) (PR #114821)

[Matt Arsenault via llvm-commits]

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@@ -933,6 +933,17 @@ class GShl : public GenericMachineInstr {
   };
 };
 
+/// Represents a logical shift right.
+class GLshr : public GenericMachineInstr {
+public:
+  Register getSrcReg() const { return getOperand(1).getReg(); }
+  Register getShiftReg() const { return getOperand(2).getReg(); }
+
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arsenm wrote:

I mean bool isExact() const { return getFlags() & IsExact; } 

https://github.com/llvm/llvm-project/pull/114821