[llvm] [llvm][CodeGen] Added a new restriction for II by pragma in window scheduler (PR #99448)
Kai Yan via llvm-commits
llvm-commits at lists.llvm.org
Sun Jul 21 20:10:12 PDT 2024
https://github.com/kaiyan96 updated https://github.com/llvm/llvm-project/pull/99448
>From 75a84b1319d6f9e665ba7b27ae5bf89b7aadb540 Mon Sep 17 00:00:00 2001
From: aklkaiyan <aklkaiyan at tencent.com>
Date: Thu, 18 Jul 2024 15:10:39 +0800
Subject: [PATCH 1/2] [llvm][CodeGen] Added a new restriction for II by pragma
in window scheduler
---
llvm/lib/CodeGen/MachinePipeliner.cpp | 8 +-
...swp-ws-pragma-initiation-interval-fail.mir | 85 +++++++++++++++++++
2 files changed, 91 insertions(+), 2 deletions(-)
create mode 100644 llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index 497e282bb9768..f97f55d2d3faa 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -528,8 +528,12 @@ bool MachinePipeliner::useSwingModuloScheduler() {
}
bool MachinePipeliner::useWindowScheduler(bool Changed) {
- // WindowScheduler does not work when it is off or when SwingModuloScheduler
- // is successfully scheduled.
+ // WindowScheduler does not work for following cases:
+ // 1. when it is off.
+ // 2. when SwingModuloScheduler is successfully scheduled.
+ // 3. when pragma II is enabled.
+ if (II_setByPragma)
+ return false;
return WindowSchedulingOption == WindowSchedulingFlag::WS_Force ||
(WindowSchedulingOption == WindowSchedulingFlag::WS_On && !Changed);
}
diff --git a/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir b/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
new file mode 100644
index 0000000000000..81dc60086ecca
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
@@ -0,0 +1,85 @@
+# RUN: llc --march=hexagon %s -run-pass=pipeliner -debug-only=pipeliner \
+# RUN: -window-sched=force -filetype=null -verify-machineinstrs 2>&1 \
+# RUN: | FileCheck %s
+# REQUIRES: asserts
+
+# Test that checks no window scheduler is performed if the II set by pragma was
+# enabled
+
+# CHECK-NOT: Start analyzing II
+# CHECK-NOT: Start scheduling Phis
+# CHECK-NOT: Current window Offset is {{[0-9]+}} and II is {{[0-9]+}}
+
+--- |
+ define void @test_pragma_ii_fail(ptr %a0, i32 %a1) {
+ b0:
+ %v0 = icmp sgt i32 %a1, 1
+ br i1 %v0, label %b1, label %b4
+
+ b1: ; preds = %b0
+ %v1 = load i32, ptr %a0, align 4
+ %v2 = add i32 %v1, 10
+ %v4 = add i32 %a1, -1
+ %cgep = getelementptr i32, ptr %a0, i32 1
+ br label %b2
+
+ b2: ; preds = %b2, %b1
+ %v5 = phi i32 [ %v12, %b2 ], [ %v4, %b1 ]
+ %v6 = phi ptr [ %cgep2, %b2 ], [ %cgep, %b1 ]
+ %v7 = phi i32 [ %v10, %b2 ], [ %v2, %b1 ]
+ store i32 %v7, ptr %v6, align 4
+ %v8 = add i32 %v7, 10
+ %cgep1 = getelementptr i32, ptr %v6, i32 -1
+ store i32 %v8, ptr %cgep1, align 4
+ %v10 = add i32 %v7, 10
+ %v12 = add i32 %v5, -1
+ %v13 = icmp eq i32 %v12, 0
+ %cgep2 = getelementptr i32, ptr %v6, i32 1
+ br i1 %v13, label %b4, label %b2, !llvm.loop !0
+
+ b4: ; preds = %b2, %b0
+ ret void
+ }
+
+ !0 = distinct !{!0, !1}
+ !1 = !{!"llvm.loop.pipeline.initiationinterval", i32 2}
+...
+---
+name: test_pragma_ii_fail
+tracksRegLiveness: true
+body: |
+ bb.0.b0:
+ successors: %bb.1(0x40000000), %bb.3(0x40000000)
+ liveins: $r0, $r1
+
+ %0:intregs = COPY $r1
+ %1:intregs = COPY $r0
+ %2:predregs = C2_cmpgti %0, 1
+ J2_jumpf %2, %bb.3, implicit-def dead $pc
+ J2_jump %bb.1, implicit-def dead $pc
+
+ bb.1.b1:
+ successors: %bb.2(0x80000000)
+
+ %3:intregs, %4:intregs = L2_loadri_pi %1, 4
+ %5:intregs = A2_addi killed %3, 10
+ %6:intregs = A2_addi %0, -1
+ %7:intregs = COPY %6
+ J2_loop0r %bb.2, %7, implicit-def $lc0, implicit-def $sa0, implicit-def $usr
+
+ bb.2.b2 (machine-block-address-taken):
+ successors: %bb.3(0x04000000), %bb.2(0x7c000000)
+
+ %8:intregs = PHI %4, %bb.1, %9, %bb.2
+ %10:intregs = PHI %5, %bb.1, %11, %bb.2
+ S2_storeri_io %8, 0, %10
+ %11:intregs = A2_addi %10, 10
+ S2_storeri_io %8, -4, %11
+ %9:intregs = A2_addi %8, 4
+ ENDLOOP0 %bb.2, implicit-def $pc, implicit-def $lc0, implicit $sa0, implicit $lc0
+ J2_jump %bb.3, implicit-def dead $pc
+
+ bb.3.b4:
+ PS_jmpret $r31, implicit-def dead $pc
+
+...
>From e3f6adafcbeaea60157af9744e056677fbe7183d Mon Sep 17 00:00:00 2001
From: aklkaiyan <aklkaiyan at tencent.com>
Date: Mon, 22 Jul 2024 11:09:01 +0800
Subject: [PATCH 2/2] [llvm][CodeGen] Modifications made for II by pragma WS
restriction based on review comments
---
llvm/lib/CodeGen/MachinePipeliner.cpp | 6 +++++-
.../Hexagon/swp-ws-pragma-initiation-interval-fail.mir | 4 +---
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index f97f55d2d3faa..c554c96a99721 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -532,8 +532,12 @@ bool MachinePipeliner::useWindowScheduler(bool Changed) {
// 1. when it is off.
// 2. when SwingModuloScheduler is successfully scheduled.
// 3. when pragma II is enabled.
- if (II_setByPragma)
+ if (II_setByPragma) {
+ LLVM_DEBUG(
+ dbgs() << "Window scheduling is disabled when Pragma II is set.\n");
return false;
+ }
+
return WindowSchedulingOption == WindowSchedulingFlag::WS_Force ||
(WindowSchedulingOption == WindowSchedulingFlag::WS_On && !Changed);
}
diff --git a/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir b/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
index 81dc60086ecca..b7b5d918488a9 100644
--- a/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
+++ b/llvm/test/CodeGen/Hexagon/swp-ws-pragma-initiation-interval-fail.mir
@@ -6,9 +6,7 @@
# Test that checks no window scheduler is performed if the II set by pragma was
# enabled
-# CHECK-NOT: Start analyzing II
-# CHECK-NOT: Start scheduling Phis
-# CHECK-NOT: Current window Offset is {{[0-9]+}} and II is {{[0-9]+}}
+# CHECK: Window scheduling is disabled when Pragma II is set.
--- |
define void @test_pragma_ii_fail(ptr %a0, i32 %a1) {
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