0f52545289
This commit introduces support for outlining functions across modules
using codegen data generated from previous codegen. The codegen data
currently manages the outlined hash tree, which records outlining
instances that occurred locally in the past.
The machine outliner now operates in one of three modes:
1. CGDataMode::None: This is the default outliner mode that uses the
suffix tree to identify (local) outlining candidates within a module.
This mode is also used by (full)LTO to maintain optimal behavior with
the combined module.
2. CGDataMode::Write (`-codegen-data-generate`): This mode is identical
to the default mode, but it also publishes the stable hash sequences of
instructions in the outlined functions into a local outlined hash tree.
It then encodes this into the `__llvm_outline` section, which will be
dead-stripped at link time.
3. CGDataMode::Read (`-codegen-data-use-path={.cgdata}`): This mode
reads a codegen data file (.cgdata) and initializes a global outlined
hash tree. This tree is used to generate global outlining candidates.
Note that the codegen data file has been post-processed with the raw
`__llvm_outline` sections from all native objects using the
`llvm-cgdata` tool (or a linker, `LLD`, or a new ThinLTO pipeline
later).
This depends on https://github.com/llvm/llvm-project/pull/105398. After
this PR, LLD (https://github.com/llvm/llvm-project/pull/90166) and Clang
(https://github.com/llvm/llvm-project/pull/90304) will follow for each
client side support.
This is a patch for
https://discourse.llvm.org/t/rfc-enhanced-machine-outliner-part-2-thinlto-nolto/78753.
101 lines
4.6 KiB
LLVM
101 lines
4.6 KiB
LLVM
; This test checks if a singleton instance (an instance that appears only once) can be outlined
|
|
; using codegen data from a previous codegen run.
|
|
; Unlike cgdata-read-single-outline.ll, this test also examines various suffixes that LLVM appends to names.
|
|
; Specifically, we aim to disregard the suffixes `.llvm.{number}` and `.__uniq.{number}` during the matching of call targets in hash computations.
|
|
; This approach helps in accurately identifying the original call target, especially when an LTO build may append additional suffixes for uniqueness.
|
|
; Conversely, we only consider the number from the suffix `.content.{number}`.
|
|
; This matching strategy is crucial for recursively finding outlining candidates when multiple outliner runs are enabled.
|
|
|
|
; RUN: split-file %s %t
|
|
|
|
; First, we generate the cgdata file from a local outline instance present in local-two.ll.
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-generate=true -filetype=obj %t/local-two.ll -o %t_write
|
|
; RUN: llvm-cgdata --merge %t_write -o %t_cgdata
|
|
; RUN: llvm-cgdata --show %t_cgdata | FileCheck %s --check-prefix=SHOW
|
|
|
|
; SHOW: Outlined hash tree:
|
|
; SHOW-NEXT: Total Node Count: 4
|
|
; SHOW-NEXT: Terminal Node Count: 1
|
|
; SHOW-NEXT: Depth: 3
|
|
|
|
; Now, we read the cgdata in the machine outliner, enabling us to optimistically
|
|
; outline a singleton instance in local-one.ll that matches against the cgdata.
|
|
; We outline instances while disregarding the suffixes `.llvm.{number}` or `.__uniq.{number}` in names.
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-use-path=%t_cgdata -filetype=obj %t/local-one-ignore-suffix-1.ll -o %t_read_ignore_1
|
|
; RUN: llvm-objdump -d %t_read_ignore_1 | FileCheck %s
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-use-path=%t_cgdata -filetype=obj %t/local-one-ignore-suffix-2.ll -o %t_read_ignore_2
|
|
; RUN: llvm-objdump -d %t_read_ignore_2 | FileCheck %s
|
|
|
|
; CHECK: _OUTLINED_FUNCTION
|
|
; CHECK-NEXT: mov
|
|
; CHECK-NEXT: mov
|
|
; CHECK-NEXT: b
|
|
|
|
; We don't ignore `.invalid.{number}`. So no outlining occurs.
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-use-path=%t_cgdata -filetype=obj %t/local-one-no-ignore-suffix.ll -o %t_read_no_ignore
|
|
; RUN: llvm-objdump -d %t_read_no_ignore | FileCheck %s --check-prefix=NOOUTLINE
|
|
|
|
; NOOUTLINE-NOT: _OUTLINED_FUNCTION
|
|
|
|
;--- local-two.ll
|
|
declare i32 @g(i32, i32, i32)
|
|
define i32 @f1() minsize {
|
|
%1 = call i32 @g(i32 10, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
define i32 @f2() minsize {
|
|
%1 = call i32 @g(i32 20, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
|
|
;--- local-one-ignore-suffix-1.ll
|
|
declare i32 @g.llvm.123(i32, i32, i32)
|
|
define i32 @f3() minsize {
|
|
%1 = call i32 @g.llvm.123(i32 30, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
|
|
;--- local-one-ignore-suffix-2.ll
|
|
declare i32 @g.__uniq.456(i32, i32, i32)
|
|
define i32 @f4() minsize {
|
|
%1 = call i32 @g.__uniq.456(i32 30, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
|
|
;--- local-one-no-ignore-suffix.ll
|
|
declare i32 @g.invalid.789(i32, i32, i32)
|
|
define i32 @f5() minsize {
|
|
%1 = call i32 @g.invalid.789(i32 30, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
|
|
; Similarly, we outline functions that have already been processed in previous outliner runs.
|
|
; Assuming `-machine-outliner-reruns` is locally enabled, we might already have `OUTLINED_FUNCTION*` instances.
|
|
; First, we generate the cgdata file from a local outline instance found in local-two-content.ll.
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-generate=true -filetype=obj %t/local-two-content.ll -o %t_write_content
|
|
; RUN: llvm-cgdata --merge %t_write_content -o %t_cgdata_content
|
|
; RUN: llvm-cgdata --show %t_cgdata_content | FileCheck %s --check-prefix=SHOW
|
|
|
|
; Despite the target function names being different -- `OUTLINED_FUNCTION_0.content.123` vs. `OUTLINED_FUNCTION_1.content.123`,
|
|
; We compute the same hash based on the suffix `.content.{number}`, and optimistically outline them.
|
|
; RUN: llc -mtriple=arm64-apple-darwin -enable-machine-outliner -codegen-data-use-path=%t_cgdata_content -filetype=obj %t/local-one-content.ll -o %t_read_content
|
|
; RUN: llvm-objdump -d %t_read_content | FileCheck %s
|
|
|
|
;--- local-two-content.ll
|
|
declare i32 @OUTLINED_FUNCTION_0.content.123(i32, i32, i32)
|
|
define i32 @f6() minsize {
|
|
%1 = call i32 @OUTLINED_FUNCTION_0.content.123(i32 10, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
define i32 @f7() minsize {
|
|
%1 = call i32 @OUTLINED_FUNCTION_0.content.123(i32 20, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|
|
|
|
;--- local-one-content.ll
|
|
declare i32 @OUTLINED_FUNCTION_1.content.123(i32, i32, i32)
|
|
define i32 @f8() minsize {
|
|
%1 = call i32 @OUTLINED_FUNCTION_1.content.123(i32 30, i32 1, i32 2);
|
|
ret i32 %1
|
|
}
|