[BOLT] Process fragment siblings in lite mode, keep lite mode on

In lite mode, include split function fragments to the list of functions to
process even if a fragment has no samples. This is required to properly
detect and update split jump tables (jump tables that contain pointers to code
in the main and cold fragments).

Reviewed By: #bolt, maksfb

Differential Revision: https://reviews.llvm.org/D140457

5 files changed, 235 insertions, 1 deletions

diff --git a/bolt/test/CMakeLists.txt b/bolt/test/CMakeLists.txt
index 898ac3ee3b85..1c7814155bda 100644
--- a/bolt/test/CMakeLists.txt
+++ b/bolt/test/CMakeLists.txt
@@ -52,6 +52,7 @@ list(APPEND BOLT_TEST_DEPS
   merge-fdata
   not
   perf2bolt
+  split-file
   yaml2obj
   )
 
diff --git a/bolt/test/X86/fragment-lite-reverse.s b/bolt/test/X86/fragment-lite-reverse.s
new file mode 100644
index 000000000000..3d681208d3e9
--- /dev/null
+++ b/bolt/test/X86/fragment-lite-reverse.s
@@ -0,0 +1,81 @@
+# Check that BOLT in lite mode processes fragments as expected.
+
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
+# RUN: link_fdata %s %t.o %t.fdata
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.out --lite=1 --data %t.fdata -v=1 2>&1 \
+# RUN:   | FileCheck %s
+
+# CHECK: BOLT-INFO: skipping processing main.cold.1 together with parent function
+# CHECK: BOLT-INFO: skipping processing foo.cold.1/1 together with parent function
+# CHECK: BOLT-INFO: skipping processing bar.cold.1/1 together with parent function
+
+  .globl main
+  .type main, %function
+main:
+  .cfi_startproc
+  cmpl	$0x0, %eax
+  je	main.cold.1
+  retq
+  .cfi_endproc
+.size main, .-main
+
+  .globl foo
+  .type foo, %function
+foo:
+  .cfi_startproc
+  cmpl	$0x0, %eax
+  je	foo.cold.1
+  retq
+  .cfi_endproc
+.size foo, .-foo
+
+  .local bar
+  .type bar, %function
+bar:
+  .cfi_startproc
+  cmpl	$0x0, %eax
+  je	bar.cold.1
+  retq
+  .cfi_endproc
+.size bar, .-bar
+
+  .section .text.cold
+  .globl main.cold.1
+  .type main.cold.1, %function
+main.cold.1:
+# FDATA: 0 [unknown] 0 1 main.cold.1 0 1 0
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size main.cold.1, .-main.cold.1
+
+  .local foo.cold.1
+  .type foo.cold.1, %function
+foo.cold.1:
+# FDATA: 0 [unknown] 0 1 foo.cold.1/1 0 1 0
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size foo.cold.1, .-foo.cold.1
+
+  .local bar.cold.1
+  .type bar.cold.1, %function
+bar.cold.1:
+# FDATA: 0 [unknown] 0 1 bar.cold.1/1 0 1 0
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size bar.cold.1, .-bar.cold.1
diff --git a/bolt/test/X86/fragment-lite.s b/bolt/test/X86/fragment-lite.s
new file mode 100644
index 000000000000..97069bf8096e
--- /dev/null
+++ b/bolt/test/X86/fragment-lite.s
@@ -0,0 +1,151 @@
+# Check that BOLT in lite mode processes fragments as expected.
+
+# RUN: split-file %s %t
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %t/main.s -o %t.o
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %t/baz.s -o %t.baz.o
+# RUN: link_fdata %s %t.o %t.main.fdata
+# RUN: link_fdata %s %t.baz.o %t.baz.fdata
+# RUN: merge-fdata %t.main.fdata %t.baz.fdata > %t.fdata
+# RUN: %clang %cflags %t.o %t.baz.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.out --lite=1 --data %t.fdata -v=1 -print-cfg \
+# RUN:   2>&1 | FileCheck %s
+
+# CHECK: BOLT-INFO: processing main.cold.1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing foo.cold.1/1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing bar.cold.1/1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing baz.cold.1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing baz.cold.1/1 as a sibling of non-ignored function
+
+# CHECK: Binary Function "main.cold.1" after building cfg
+# CHECK: Parent : main
+
+# CHECK: Binary Function "foo.cold.1/1" after building cfg
+# CHECK: Parent : foo
+
+# CHECK: Binary Function "bar.cold.1/1" after building cfg
+# CHECK: Parent : bar/1
+
+# CHECK: Binary Function "baz.cold.1" after building cfg
+# CHECK: Parent : baz{{$}}
+
+# CHECK: Binary Function "baz.cold.1/1" after building cfg
+# CHECK: Parent : baz/1
+
+#--- main.s
+  .globl main
+  .type main, %function
+main:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 main 0 1 0
+  cmpl	$0x0, %eax
+  je	main.cold.1
+  retq
+  .cfi_endproc
+.size main, .-main
+
+  .globl foo
+  .type foo, %function
+foo:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 foo 0 1 0
+  cmpl	$0x0, %eax
+  je	foo.cold.1
+  retq
+  .cfi_endproc
+.size foo, .-foo
+
+  .local bar
+  .type bar, %function
+bar:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 bar/1 0 1 0
+  cmpl	$0x0, %eax
+  je	bar.cold.1
+  retq
+  .cfi_endproc
+.size bar, .-bar
+
+  .globl baz
+  .type baz, %function
+baz:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 baz 0 1 0
+  cmpl	$0x0, %eax
+  je	baz.cold.1
+  retq
+  .cfi_endproc
+.size baz, .-baz
+
+  .section .text.cold
+  .globl main.cold.1
+  .type main.cold.1, %function
+main.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size main.cold.1, .-main.cold.1
+
+  .local foo.cold.1
+  .type foo.cold.1, %function
+foo.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size foo.cold.1, .-foo.cold.1
+
+  .local bar.cold.1
+  .type bar.cold.1, %function
+bar.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size bar.cold.1, .-bar.cold.1
+
+  .globl baz.cold.1
+  .type baz.cold.1, %function
+baz.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size baz.cold.1, .-baz.cold.1
+
+#--- baz.s
+  .local baz
+  .type baz, %function
+baz:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 baz/1 0 1 0
+  cmpl	$0x0, %eax
+  je	baz.cold.1
+  retq
+  .cfi_endproc
+.size baz, .-baz
+
+  .section .text.cold
+  .local baz.cold.1
+  .type baz.cold.1, %function
+baz.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size baz.cold.1, .-baz.cold.1
diff --git a/bolt/test/X86/split-func-icf.s b/bolt/test/X86/split-func-icf.s
index eac4174fefd5..259c30186400 100644
--- a/bolt/test/X86/split-func-icf.s
+++ b/bolt/test/X86/split-func-icf.s
@@ -11,8 +11,8 @@
 # RUN: llvm-bolt %t.exe -o %t.out -v=1 --print-only=main2.cold.1 --print-disasm 2>&1 | FileCheck %s
 
 # CHECK-NOT: unclaimed PC-relative relocations left in data
-# CHECK-DAG: BOLT-INFO: marking main2.cold.1(*2) as a fragment of main
 # CHECK-DAG: BOLT-INFO: marking main2.cold.1(*2) as a fragment of main2
+# CHECK-DAG: BOLT-INFO: marking main2.cold.1(*2) as a fragment of main
 # CHECK: Binary Function "main2.cold.1(*2)" after disassembly
 # CHECK: End of Function "main2.cold.1(*2)"
 # CHECK-DAG: BOLT-WARNING: Ignoring main2
diff --git a/bolt/test/lit.cfg.py b/bolt/test/lit.cfg.py
index 87d437c2277c..b5e15e20b1fe 100644
--- a/bolt/test/lit.cfg.py
+++ b/bolt/test/lit.cfg.py
@@ -93,6 +93,7 @@ tools = [
     ToolSubst('merge-fdata', unresolved='fatal'),
     ToolSubst('llvm-readobj', unresolved='fatal'),
     ToolSubst('llvm-dwp', unresolved='fatal'),
+    ToolSubst('split-file', unresolved='fatal'),
 ]
 llvm_config.add_tool_substitutions(tools, tool_dirs)