[llvm][MIRVRegNamerUtils] Adding hashing on FrameIndex MachineOperands.

This patch makes it so that cases where multiple instructions that differ only
in their FrameIndex MachineOperand values no longer collide. For instance:

%1:_(p0) = G_FRAME_INDEX %stack.0
%2:_(p0) = G_FRAME_INDEX %stack.1

Prior to this patch these instructions would collide together.

Differential Revision: https://reviews.llvm.org/D71583

Author: plotfi

llvm/lib/CodeGen/MIRVRegNamerUtils.cpp

@@ -68,6 +68,8 @@ std::string VRegRenamer::getInstructionOpcodeHash(MachineInstr &MI) {
       return MO.getImm();
     case MachineOperand::MO_TargetIndex:
       return MO.getOffset() | (MO.getTargetFlags() << 16);
+    case MachineOperand::MO_FrameIndex:
+      return llvm::hash_value(MO);
 
     // We could explicitly handle all the types of the MachineOperand,
     // here but we can just return a common number until we find a
@@ -77,7 +79,6 @@ std::string VRegRenamer::getInstructionOpcodeHash(MachineInstr &MI) {
 
     // TODO: Handle the following Index/ID/Predicate cases. They can
     // be hashed on in a stable manner.
-    case MachineOperand::MO_FrameIndex:
     case MachineOperand::MO_ConstantPoolIndex:
     case MachineOperand::MO_JumpTableIndex:
     case MachineOperand::MO_CFIIndex:

llvm/test/CodeGen/MIR/X86/mir-namer-hash-frameindex.mir

@@ -0,0 +1,23 @@
+# RUN: llc -mtriple x86_64-linux-gnu -run-pass mir-canonicalizer -verify-machineinstrs %s -o - | FileCheck %s
+
+...
+---
+name: f
+stack:
+  - { id: 0, size: 4 }
+  - { id: 1, size: 4 }
+fixedStack:
+  - { id: 0, offset: 0, size: 4 }
+  - { id: 1, offset: 0, size: 4 }
+body: |
+  bb.1:
+    ; CHECK: _1:_(p0) = G_FRAME_INDEX %stack.{{[0-1]}}
+    ; CHECK: _1:_(p0) = G_FRAME_INDEX %stack.{{[0-1]}}
+    ; CHECK: _1:gr32 = MOV32rm %fixed-stack.{{[0-1]}}
+    ; CHECK: _1:gr32 = MOV32rm %fixed-stack.{{[0-1]}}
+    %1:_(p0) = G_FRAME_INDEX %stack.0
+    %2:_(p0) = G_FRAME_INDEX %stack.1
+    %3:gr32 = MOV32rm %fixed-stack.0, 1, _, 0, _
+    %4:gr32 = MOV32rm %fixed-stack.1, 1, _, 0, _
+
+...