From 1f2dd7f40a36c6987f6102501b567b9171e5afb5 Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <gardener@tensorflow.org>
Date: Fri, 13 Dec 2024 07:12:51 -0800
Subject: [PATCH] Integrate LLVM at llvm/llvm-project@5e53a8dadb00

Updates LLVM usage to match
[5e53a8dadb00](https://github.com/llvm/llvm-project/commit/5e53a8dadb00)

PiperOrigin-RevId: 705873858
---
 third_party/llvm/generated.patch | 34 ++++++++++++++++++++++++++++++++
 third_party/llvm/workspace.bzl   |  4 ++--
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/third_party/llvm/generated.patch b/third_party/llvm/generated.patch
index 509398da9..42c41389c 100644
--- a/third_party/llvm/generated.patch
+++ b/third_party/llvm/generated.patch
@@ -1 +1,35 @@
 Auto generated patch. Do not edit or delete it, even if empty.
+diff -ruN --strip-trailing-cr a/llvm/lib/CodeGen/MLRegAllocEvictAdvisor.cpp b/llvm/lib/CodeGen/MLRegAllocEvictAdvisor.cpp
+--- a/llvm/lib/CodeGen/MLRegAllocEvictAdvisor.cpp
++++ b/llvm/lib/CodeGen/MLRegAllocEvictAdvisor.cpp
+@@ -63,6 +63,12 @@
+         "outgoing name should be "
+         "<regalloc-evict-interactive-channel-base>.out"));
+ 
++static cl::opt<unsigned>
++    MaxCascade("mlregalloc-max-cascade", cl::Hidden,
++               cl::desc("The maximum number of times a live range can be "
++                        "evicted before preventing it from being evicted"),
++               cl::init(20));
++
+ // Options that only make sense in development mode
+ #ifdef LLVM_HAVE_TFLITE
+ #include "RegAllocScore.h"
+@@ -643,8 +649,16 @@
+            RegClassInfo.getNumAllocatableRegs(MRI->getRegClass(VirtReg.reg())) <
+                RegClassInfo.getNumAllocatableRegs(
+                    MRI->getRegClass(Intf->reg())));
+-      // Only evict older cascades or live ranges without a cascade.
++
+       unsigned IntfCascade = RA.getExtraInfo().getCascade(Intf->reg());
++      // There is a potential that the model could be adversarial and
++      // continually evict live ranges over and over again, leading to a
++      // large amount of compile time being spent in regalloc. If we hit the
++      // threshold, prevent the range from being evicted.
++      if (IntfCascade >= MaxCascade)
++        return false;
++
++      // Only evict older cascades or live ranges without a cascade.
+       if (Cascade <= IntfCascade) {
+         if (!Urgent)
+           return false;
diff --git a/third_party/llvm/workspace.bzl b/third_party/llvm/workspace.bzl
index bf592d974..094e5680c 100644
--- a/third_party/llvm/workspace.bzl
+++ b/third_party/llvm/workspace.bzl
@@ -4,8 +4,8 @@ load("//third_party:repo.bzl", "tf_http_archive")
 
 def repo(name):
     """Imports LLVM."""
-    LLVM_COMMIT = "0876c11ceeb093904decc4d89bef213d483a5656"
-    LLVM_SHA256 = "8379577a71645bbba89dea08beba32b3e56b833da7340ba5be7efa3986c8f8ed"
+    LLVM_COMMIT = "5e53a8dadb0019ee87936c1278fa222781257005"
+    LLVM_SHA256 = "eb8e26186a8f7e15e59d37729353525d2367272c9f053d2ef1a2c1e292b8b688"
 
     tf_http_archive(
         name = name,