From 6fa6974e8dd0a1ae03771c98a1dfff5c29d56160 Mon Sep 17 00:00:00 2001
From: Tim Shen <timshen@google.com>
Date: Wed, 10 Feb 2021 19:44:15 -0800
Subject: [PATCH] [XLA/GPU] Plumb through Bitcast op for LMHLO.

Also remove BitcastOp. XLA bitcast requires the input buffer to alias the output buffer, which makes bitcast always a no-op.

PiperOrigin-RevId: 356884383
---
 include/mlir-hlo/Dialect/mhlo/IR/lhlo_ops.td | 6 ------
 tests/lhlo_ops.mlir                          | 8 --------
 2 files changed, 14 deletions(-)

diff --git a/include/mlir-hlo/Dialect/mhlo/IR/lhlo_ops.td b/include/mlir-hlo/Dialect/mhlo/IR/lhlo_ops.td
index fb1e176..d723aad 100644
--- a/include/mlir-hlo/Dialect/mhlo/IR/lhlo_ops.td
+++ b/include/mlir-hlo/Dialect/mhlo/IR/lhlo_ops.td
@@ -380,12 +380,6 @@ def LHLO_BatchNormTrainingOp : LHLO_Op<"batch_norm_training", []>,
   );
 }
 
-// TODO(timshen): add a custom verifier.
-def LHLO_BitcastOp: LHLO_Op<"bitcast", []> {
-  let arguments = (ins Arg<LHLO_Buffer, "", [MemRead]>:$input,
-                       Arg<LHLO_Buffer, "", [MemWrite]>:$output);
-}
-
 def LHLO_BroadcastOp : LHLO_Op<"broadcast",
       []>, BASE_HLO_BroadcastOp {
   let arguments = (ins
diff --git a/tests/lhlo_ops.mlir b/tests/lhlo_ops.mlir
index b01beb7..021ea31 100644
--- a/tests/lhlo_ops.mlir
+++ b/tests/lhlo_ops.mlir
@@ -899,14 +899,6 @@ func @while_memrefs(%arg0: memref<i64>, %arg1: memref<5xf32>, %arg0_out: memref<
 
 // -----
 
-// CHECK-LABEL: func @bitcast_memrefs
-func @bitcast_memrefs(%arg0: memref<1xf64>, %arg_out: memref<2xi32>) -> () {
-  "lmhlo.bitcast"(%arg0, %arg_out) : (memref<1xf64>, memref<2xi32>) -> ()
-  return
-}
-
-// -----
-
 // CHECK-LABEL: func @scatter_memrefs
 func @scatter_memrefs(%input: memref<200x100x300xf32>, %indices: memref<10x2xi32>,
                       %updates: memref<10x300xf32>, %arg_out: memref<200x100x300xf32>) -> () {