[llvm] [BOLT] Improve BinaryFunction::inferFallThroughCounts() (PR #105450)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 20 19:08:52 PDT 2024
https://github.com/ShatianWang updated https://github.com/llvm/llvm-project/pull/105450
>From e903d5fc4e7bffc51033416567e3954f7ebb9b69 Mon Sep 17 00:00:00 2001
From: Shatian Wang <shatian at meta.com>
Date: Tue, 20 Aug 2024 16:14:32 -0700
Subject: [PATCH 1/4] [BOLT] Improve BinaryFunction::inferFallThroughCounts()
---
bolt/lib/Core/BinaryFunctionProfile.cpp | 3 +-
bolt/test/X86/infer-fall-throughs.s | 71 +++++++++++++++++++++++++
2 files changed, 73 insertions(+), 1 deletion(-)
create mode 100644 bolt/test/X86/infer-fall-throughs.s
diff --git a/bolt/lib/Core/BinaryFunctionProfile.cpp b/bolt/lib/Core/BinaryFunctionProfile.cpp
index 55ebe5fc900e65..726da6a9d0829f 100644
--- a/bolt/lib/Core/BinaryFunctionProfile.cpp
+++ b/bolt/lib/Core/BinaryFunctionProfile.cpp
@@ -336,7 +336,8 @@ void BinaryFunction::inferFallThroughCounts() {
if (SuccBI.Count == 0) {
SuccBI.Count = Inferred;
SuccBI.MispredictedCount = BinaryBasicBlock::COUNT_INFERRED;
- Succ->ExecutionCount += Inferred;
+ Succ->ExecutionCount =
+ std::max(Succ->getKnownExecutionCount(), Inferred);
}
}
}
diff --git a/bolt/test/X86/infer-fall-throughs.s b/bolt/test/X86/infer-fall-throughs.s
new file mode 100644
index 00000000000000..9a35fd33b299bb
--- /dev/null
+++ b/bolt/test/X86/infer-fall-throughs.s
@@ -0,0 +1,71 @@
+## Test that infer-fall-throughs would correctly infer the wrong fall-through
+## edge count in the example
+
+# RUN: llvm-mc --filetype=obj --triple x86_64-unknown-unknown %s -o %t.o
+# RUN: link_fdata %s %t.o %t.fdata
+# RUN: llvm-strip --strip-unneeded %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt --split-functions \
+# RUN: --print-split --print-only=chain --data=%t.fdata \
+# RUN: --reorder-blocks=none \
+# RUN: 2>&1 | FileCheck --check-prefix=WITHOUTINFERENCE %s
+# RUN: llvm-bolt %t.exe -o %t.bolt --split-functions --infer-fall-throughs \
+# RUN: --print-split --print-only=chain --data=%t.fdata \
+# RUN: --reorder-blocks=none \
+# RUN: 2>&1 | FileCheck --check-prefix=CORRECTINFERENCE %s
+
+
+# WITHOUTINFERENCE: Binary Function "chain" after split-functions
+# WITHOUTINFERENCE: {{^\.LBB00}}
+# WITHOUTINFERENCE: Successors: .Ltmp0 (mispreds: 0, count: 10), .LFT0 (mispreds: 0, count: 0)
+# WITHOUTINFERENCE: {{^\.LFT0}}
+# WITHOUTINFERENCE: Exec Count : 490
+
+# CORRECTINFERENCE: Binary Function "chain" after split-functions
+# CORRECTINFERENCE: {{^\.LBB00}}
+# CORRECTINFERENCE: Successors: .Ltmp0 (mispreds: 0, count: 10), .LFT0 (inferred count: 490)
+# CORRECTINFERENCE: {{^\.LFT0}}
+# CORRECTINFERENCE: Exec Count : 490
+
+
+ .text
+ .globl chain
+ .type chain, @function
+chain:
+ pushq %rbp
+ movq %rsp, %rbp
+ cmpl $2, %edi
+LLstart:
+ jge LLless
+# FDATA: 1 chain #LLstart# 1 chain #LLless# 0 10
+# FDATA: 1 chain #LLstart# 1 chain #LLmore# 0 0
+LLmore:
+ movl $5, %eax
+LLmore_LLexit:
+ jmp LLexit
+# FDATA: 1 chain #LLmore_LLexit# 1 chain #LLexit# 0 490
+LLless:
+ movl $10, %eax
+LLdummy:
+ jmp LLexit
+# FDATA: 1 chain #LLdummy# 1 chain #LLexit# 0 10
+LLexit:
+ popq %rbp
+ ret
+LLchain_end:
+ .size chain, LLchain_end-chain
+
+
+ .globl main
+ .type main, @function
+main:
+ pushq %rbp
+ movq %rsp, %rbp
+ movl $1, %edi
+LLmain_chain:
+ call chain
+# FDATA: 1 main #LLmain_chain# 1 chain 0 0 500
+ movl $4, %edi
+ retq
+.Lmain_end:
+ .size main, .Lmain_end-main
>From 14564bf388fce7655652deb4a60fe090049563f9 Mon Sep 17 00:00:00 2001
From: Shatian Wang <shatian at meta.com>
Date: Tue, 20 Aug 2024 18:45:23 -0700
Subject: [PATCH 2/4] fixup! [BOLT] Improve
BinaryFunction::inferFallThroughCounts()
---
bolt/test/X86/infer-fall-throughs.s | 65 ++++++++++-------------------
1 file changed, 22 insertions(+), 43 deletions(-)
diff --git a/bolt/test/X86/infer-fall-throughs.s b/bolt/test/X86/infer-fall-throughs.s
index 9a35fd33b299bb..d718d37b8bad12 100644
--- a/bolt/test/X86/infer-fall-throughs.s
+++ b/bolt/test/X86/infer-fall-throughs.s
@@ -5,67 +5,46 @@
# RUN: link_fdata %s %t.o %t.fdata
# RUN: llvm-strip --strip-unneeded %t.o
# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
-# RUN: llvm-bolt %t.exe -o %t.bolt --split-functions \
-# RUN: --print-split --print-only=chain --data=%t.fdata \
-# RUN: --reorder-blocks=none \
+# RUN: llvm-bolt %t.exe -o %t.bolt \
+# RUN: --print-estimate-edge-counts --data=%t.fdata \
# RUN: 2>&1 | FileCheck --check-prefix=WITHOUTINFERENCE %s
-# RUN: llvm-bolt %t.exe -o %t.bolt --split-functions --infer-fall-throughs \
-# RUN: --print-split --print-only=chain --data=%t.fdata \
-# RUN: --reorder-blocks=none \
+# RUN: llvm-bolt %t.exe -o %t.bolt --infer-fall-throughs \
+# RUN: --print-estimate-edge-counts --data=%t.fdata \
# RUN: 2>&1 | FileCheck --check-prefix=CORRECTINFERENCE %s
-# WITHOUTINFERENCE: Binary Function "chain" after split-functions
-# WITHOUTINFERENCE: {{^\.LBB00}}
-# WITHOUTINFERENCE: Successors: .Ltmp0 (mispreds: 0, count: 10), .LFT0 (mispreds: 0, count: 0)
+# WITHOUTINFERENCE: Binary Function "main" after estimate-edge-counts
+# WITHOUTINFERENCE: {{^\.Ltmp0}}
+# WITHOUTINFERENCE: Successors: .Ltmp1 (mispreds: 0, count: 10), .LFT0 (mispreds: 0, count: 0)
# WITHOUTINFERENCE: {{^\.LFT0}}
# WITHOUTINFERENCE: Exec Count : 490
-# CORRECTINFERENCE: Binary Function "chain" after split-functions
-# CORRECTINFERENCE: {{^\.LBB00}}
-# CORRECTINFERENCE: Successors: .Ltmp0 (mispreds: 0, count: 10), .LFT0 (inferred count: 490)
+# CORRECTINFERENCE: Binary Function "main" after estimate-edge-counts
+# CORRECTINFERENCE: {{^\.Ltmp0}}
+# CORRECTINFERENCE: Successors: .Ltmp1 (mispreds: 0, count: 10), .LFT0 (inferred count: 490)
# CORRECTINFERENCE: {{^\.LFT0}}
# CORRECTINFERENCE: Exec Count : 490
- .text
- .globl chain
- .type chain, @function
-chain:
- pushq %rbp
- movq %rsp, %rbp
- cmpl $2, %edi
+ .globl main
+ .type main, @function
+main:
+LLmain_LLstart:
+ jmp LLstart
+# FDATA: 1 main #LLmain_LLstart# 1 main #LLstart# 0 500
LLstart:
jge LLless
-# FDATA: 1 chain #LLstart# 1 chain #LLless# 0 10
-# FDATA: 1 chain #LLstart# 1 chain #LLmore# 0 0
+# FDATA: 1 main #LLstart# 1 main #LLless# 0 10
+# FDATA: 1 main #LLstart# 1 main #LLmore# 0 0
LLmore:
movl $5, %eax
LLmore_LLexit:
jmp LLexit
-# FDATA: 1 chain #LLmore_LLexit# 1 chain #LLexit# 0 490
+# FDATA: 1 main #LLmore_LLexit# 1 main #LLexit# 0 490
LLless:
- movl $10, %eax
-LLdummy:
jmp LLexit
-# FDATA: 1 chain #LLdummy# 1 chain #LLexit# 0 10
+# FDATA: 1 main #LLless# 1 main #LLexit# 0 10
LLexit:
- popq %rbp
ret
-LLchain_end:
- .size chain, LLchain_end-chain
-
-
- .globl main
- .type main, @function
-main:
- pushq %rbp
- movq %rsp, %rbp
- movl $1, %edi
-LLmain_chain:
- call chain
-# FDATA: 1 main #LLmain_chain# 1 chain 0 0 500
- movl $4, %edi
- retq
-.Lmain_end:
- .size main, .Lmain_end-main
+.LLmain_end:
+ .size main, .LLmain_end-main
>From 4af894a12e0df8871b679f0a3eb00e77b5f35c75 Mon Sep 17 00:00:00 2001
From: Shatian Wang <shatian at meta.com>
Date: Tue, 20 Aug 2024 19:03:50 -0700
Subject: [PATCH 3/4] fixup! fixup! [BOLT] Improve
BinaryFunction::inferFallThroughCounts()
---
bolt/test/X86/infer-fall-throughs.s | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/bolt/test/X86/infer-fall-throughs.s b/bolt/test/X86/infer-fall-throughs.s
index d718d37b8bad12..086f37390f6a44 100644
--- a/bolt/test/X86/infer-fall-throughs.s
+++ b/bolt/test/X86/infer-fall-throughs.s
@@ -33,17 +33,14 @@ LLmain_LLstart:
jmp LLstart
# FDATA: 1 main #LLmain_LLstart# 1 main #LLstart# 0 500
LLstart:
- jge LLless
-# FDATA: 1 main #LLstart# 1 main #LLless# 0 10
+ jge LLexit
+# FDATA: 1 main #LLstart# 1 main #LLexit# 0 10
# FDATA: 1 main #LLstart# 1 main #LLmore# 0 0
LLmore:
movl $5, %eax
LLmore_LLexit:
jmp LLexit
# FDATA: 1 main #LLmore_LLexit# 1 main #LLexit# 0 490
-LLless:
- jmp LLexit
-# FDATA: 1 main #LLless# 1 main #LLexit# 0 10
LLexit:
ret
.LLmain_end:
>From d2f507a3b3f493fb8421834c01f36f10c0dae194 Mon Sep 17 00:00:00 2001
From: Shatian Wang <shatian at meta.com>
Date: Tue, 20 Aug 2024 19:08:36 -0700
Subject: [PATCH 4/4] fixup! fixup! fixup! [BOLT] Improve
BinaryFunction::inferFallThroughCounts()
---
bolt/test/X86/infer-fall-throughs.s | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/bolt/test/X86/infer-fall-throughs.s b/bolt/test/X86/infer-fall-throughs.s
index 086f37390f6a44..3289a8ea4aec51 100644
--- a/bolt/test/X86/infer-fall-throughs.s
+++ b/bolt/test/X86/infer-fall-throughs.s
@@ -38,9 +38,7 @@ LLstart:
# FDATA: 1 main #LLstart# 1 main #LLmore# 0 0
LLmore:
movl $5, %eax
-LLmore_LLexit:
- jmp LLexit
-# FDATA: 1 main #LLmore_LLexit# 1 main #LLexit# 0 490
+# FDATA: 1 main #LLmore# 1 main #LLexit# 0 490
LLexit:
ret
.LLmain_end:
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