https://github.com/kartcq updated
https://github.com/llvm/llvm-project/pull/75141
>From 98745d850c588eaf9b5d2ac6f71c79873107501f Mon Sep 17 00:00:00 2001
From: kartcq
Date: Mon, 11 Dec 2023 05:22:33 -0800
Subject: [PATCH 1/4] [polly][ScheduleOptimizer] Bail out on exceeding Schedule
compute's ISL quota
There is no upper cap set on current Schedule Optimizer to compute schedule. In
some cases a very long compile time taken to compute the schedule resulting in
hang kind of behavior. This patch introduces a flag 'polly-schedule-computeout'
to pass the cap which is initialized to 30. This patch handles the compute
out cases by bailing out and exiting gracefully.
Change-Id: Id506832df4ae8d3f140579ba10cf570e18efac62
---
polly/lib/Transform/ScheduleOptimizer.cpp | 25 +
.../ScheduleOptimizer/schedule_computeout.ll | 97 +++
2 files changed, 122 insertions(+)
create mode 100644 polly/test/ScheduleOptimizer/schedule_computeout.ll
diff --git a/polly/lib/Transform/ScheduleOptimizer.cpp
b/polly/lib/Transform/ScheduleOptimizer.cpp
index 35a0a4def0403d..8ee2b66339adbc 100644
--- a/polly/lib/Transform/ScheduleOptimizer.cpp
+++ b/polly/lib/Transform/ScheduleOptimizer.cpp
@@ -96,6 +96,13 @@ static cl::opt
cl::desc("Maximize the band depth (yes/no)"), cl::Hidden,
cl::init("yes"), cl::cat(PollyCategory));
+static cl::opt
+ScheduleComputeOut("polly-schedule-computeout",
+ cl::desc("Bound the scheduler by maximal amount"
+"of computational steps. "),
+ cl::Hidden, cl::init(30), cl::ZeroOrMore,
+ cl::cat(PollyCategory));
+
static cl::opt
GreedyFusion("polly-loopfusion-greedy",
cl::desc("Aggressively try to fuse everything"), cl::Hidden,
@@ -860,7 +867,25 @@ static void runIslScheduleOptimizer(
SC = SC.set_proximity(Proximity);
SC = SC.set_validity(Validity);
SC = SC.set_coincidence(Validity);
+
+// Save error handling behavior
+long MaxOperations = isl_ctx_get_max_operations(Ctx);
+isl_ctx_set_max_operations(Ctx, ScheduleComputeOut);
Schedule = SC.compute_schedule();
+bool ScheduleQuota = false;
+if (isl_ctx_last_error(Ctx) == isl_error_quota) {
+ isl_ctx_reset_error(Ctx);
+ LLVM_DEBUG(
+ dbgs() << "Schedule optimizer calculation exceeds ISL quota\n");
+ ScheduleQuota = true;
+}
+isl_options_set_on_error(Ctx, ISL_ON_ERROR_ABORT);
+isl_ctx_reset_operations(Ctx);
+isl_ctx_set_max_operations(Ctx, MaxOperations);
+
+if (ScheduleQuota)
+ return;
+
isl_options_set_on_error(Ctx, OnErrorStatus);
ScopsRescheduled++;
diff --git a/polly/test/ScheduleOptimizer/schedule_computeout.ll
b/polly/test/ScheduleOptimizer/schedule_computeout.ll
new file mode 100644
index 00..3e768e02c8a740
--- /dev/null
+++ b/polly/test/ScheduleOptimizer/schedule_computeout.ll
@@ -0,0 +1,97 @@
+; RUN: opt -S -polly-optree -polly-delicm -polly-opt-isl
-polly-schedule-computeout=10 -debug-only="polly-opt-isl" < %s 2>&1 |
FileCheck %s
+; Bailout if the computations of schedule compute exceeds the max scheduling
quota.
+; Max compute out is initialized to 30, Here it is set to 10 for test
purpose.
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64-unknown-linux-gnu"
+
+@a = dso_local local_unnamed_addr global ptr null, align 8
+@b = dso_local local_unnamed_addr global ptr null, align 8
+@c = dso_local local_unnamed_addr global ptr null, align 8
+
+define dso_local void @foo(i32 noundef %I, i32 noundef %J, i32 noundef %K1,
i32 noundef %K2, i32 noundef %L1, i32 noundef %L2) local_unnamed_addr {
+entry:
+ %j = alloca i32, align 4
+ store volatile i32 0, ptr %j, align 4
+ %j.0.j.0.j.0.54 = load volatile i32, ptr %j, align 4
+ %cmp55 = icmp slt i32 %j.0.j.0.j.0.54, %J
+ br i1 %cmp55, label %for.body.lr.ph, label %for.cond.cleanup
+
+for.body.lr.ph: ; preds = %entry
+ %0 = load ptr, ptr @a, align 8
+ %1 = load ptr, ptr @b, align 8
+ %2 = load ptr, ptr %1, align 8
+ %cmp352 = icmp slt i32 %L1, %L2
+ %cmp750 = icmp slt i32 %K1, %K2
+ %3 = sext i32 %K1 to i64
+ %4 = sext i32 %L1 to i64
+ br label %for.body
+
+for.cond.cleanup: ; preds =
%for.cond.cleanup4, %entry
+ ret void
+
+for.body: ; preds =
%for.cond.cleanup4, %for.body.lr.ph
+ br i1 %cmp352, label %for.cond6.preheader.preheader, label %for.cond.cleanup4
+
+for.cond6.preheader.preheader:; preds = %for.body
+ %wide.trip.count66 = sext i32 %L2 to i64
+ br label %for.cond6.preheader
+
+for.cond6.preheader: ; preds =
%for.cond.cleanup8, %for.cond6.preheader.preheader
+ %indvars.iv61 = phi i64 [ %4, %for.cond6.preheader.preheader ], [
%indvars.iv.next62,
