From cf34559104d3531e98e16ea242b777f18d5f95cf Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Thu, 18 Feb 2021 18:50:58 -0800
Subject: [PATCH] [RISCV] Enable PrimaryKeyEarlyOut on RISCVVPseudosTable.

This table is queried in RISCVMCInstLower without knowing
whether the instruction is a vector pseudo. Due to the way the
binary search works, we have to do log2(tablesize) checks just
to determine a non-vector instruction isn't in the table.

Conveniently, all the vector pseudos are pretty tightly
packed within the internal instruction enum. By enabling the
PrimaryKeyEarlyOut, tablegen will emit a check against the
beginning and end of the table before doing the binary search.
This gives a quick early out on the search for the majority
of non-vector instructions.

Differential Revision: https://reviews.llvm.org/D97016
---
 llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td b/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
index 4e3a261ba299..20f37400bd7f 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
@@ -402,6 +402,7 @@ def RISCVVPseudosTable : GenericTable {
   let Fields = [ "Pseudo", "BaseInstr" ];
   let PrimaryKey = [ "Pseudo" ];
   let PrimaryKeyName = "getPseudoInfo";
+  let PrimaryKeyEarlyOut = true;
 }
 
 def RISCVVIntrinsicsTable : GenericTable {