From cc2c45dc54b324727a00be7218f387fcb53dd6c7 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Mon, 8 Feb 2021 09:48:25 -0800
Subject: [PATCH] [RISCV] Use SplatPat/SplatPat_simm5 to handle
 PseudoVMV_V_X_/PseudoVMV_V_I_ selection as well.

This ensures that we'll match immediates consistently regardless
of whether we match them as a standalone splat or as part of
another operation.

While I was there I added complexities to the simm5/uimm5 patterns so
we didn't have to assume that the 1 on the non-immediate was lower
than what tablegen inferred.

I had to make a minor tweak to tablegen to fix one place that
didn't expect to see a ComplexPattern that wasn't a "leaf".

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D96199
---
 llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td | 27 +++++-----------------
 llvm/utils/TableGen/CodeGenDAGPatterns.cpp         |  3 +++
 2 files changed, 9 insertions(+), 21 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td b/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
index e18a46a..e1ae6f9 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
@@ -32,12 +32,10 @@ def riscv_trunc_vector : SDNode<"RISCVISD::TRUNCATE_VECTOR",
                                 SDTypeProfile<1, 1,
                                  [SDTCisVec<0>, SDTCisVec<1>]>>;
 
-// Penalize the generic form with Complexity=1 to give the simm5/uimm5 variants
-// precedence
-def SplatPat       : ComplexPattern<vAny, 1, "selectVSplat", [], [], 1>;
-
-def SplatPat_simm5 : ComplexPattern<vAny, 1, "selectVSplatSimm5", []>;
-def SplatPat_uimm5 : ComplexPattern<vAny, 1, "selectVSplatUimm5", []>;
+// Give explicit Complexity to prefer simm5/uimm5.
+def SplatPat       : ComplexPattern<vAny, 1, "selectVSplat",      [splat_vector, rv32_splat_i64], [], 1>;
+def SplatPat_simm5 : ComplexPattern<vAny, 1, "selectVSplatSimm5", [splat_vector, rv32_splat_i64], [], 2>;
+def SplatPat_uimm5 : ComplexPattern<vAny, 1, "selectVSplatUimm5", [splat_vector, rv32_splat_i64], [], 2>;
 
 def RVVBaseAddr : ComplexPattern<iPTR, 1, "SelectRVVBaseAddr">;
 
@@ -714,10 +712,10 @@ foreach fvtiToFWti = AllWidenableFloatVectors in {
 
 let Predicates = [HasStdExtV] in {
 foreach vti = AllIntegerVectors in {
-  def : Pat<(vti.Vector (splat_vector GPR:$rs1)),
+  def : Pat<(vti.Vector (SplatPat GPR:$rs1)),
             (!cast<Instruction>("PseudoVMV_V_X_" # vti.LMul.MX)
               GPR:$rs1, vti.AVL, vti.SEW)>;
-  def : Pat<(vti.Vector (splat_vector simm5:$rs1)),
+  def : Pat<(vti.Vector (SplatPat_simm5 simm5:$rs1)),
             (!cast<Instruction>("PseudoVMV_V_I_" # vti.LMul.MX)
               simm5:$rs1, vti.AVL, vti.SEW)>;
 }
@@ -730,19 +728,6 @@ foreach mti = AllMasks in {
 }
 } // Predicates = [HasStdExtV]
 
-let Predicates = [HasStdExtV, IsRV32] in {
-foreach vti = AllIntegerVectors in {
-  if !eq(vti.SEW, 64) then {
-    def : Pat<(vti.Vector (rv32_splat_i64 GPR:$rs1)),
-              (!cast<Instruction>("PseudoVMV_V_X_" # vti.LMul.MX)
-                GPR:$rs1, vti.AVL, vti.SEW)>;
-    def : Pat<(vti.Vector (rv32_splat_i64 simm5:$rs1)),
-              (!cast<Instruction>("PseudoVMV_V_I_" # vti.LMul.MX)
-                simm5:$rs1, vti.AVL, vti.SEW)>;
-  }
-}
-} // Predicates = [HasStdExtV, IsRV32]
-
 let Predicates = [HasStdExtV, HasStdExtF] in {
 foreach fvti = AllFloatVectors in {
   def : Pat<(fvti.Vector (splat_vector fvti.ScalarRegClass:$rs1)),
diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index 394a0e1..0bfb695 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -3472,6 +3472,9 @@ private:
     if (N->getNumChildren() != 1 || !N->getChild(0)->isLeaf())
       return false;
 
+    if (N->getOperator()->isSubClassOf("ComplexPattern"))
+      return false;
+
     const SDNodeInfo &OpInfo = CDP.getSDNodeInfo(N->getOperator());
     if (OpInfo.getNumResults() != 1 || OpInfo.getNumOperands() != 1)
       return false;
-- 
2.7.4