llvm/test/ThinLTO/X86/autoupgrade.ll
Peter Collingbourne 6163b4af73 Bitcode: Add a string table to the bitcode format.
Add a top-level STRTAB block containing a string table blob, and start storing
strings for module codes FUNCTION, GLOBALVAR, ALIAS, IFUNC and COMDAT in
the string table.

This change allows us to share names between globals and comdats as well
as between modules, and improves the efficiency of loading bitcode files by
no longer using a bit encoding for symbol names. Once we start writing the
irsymtab to the bitcode file we will also be able to share strings between
it and the module.

On my machine, link time for Chromium for Linux with ThinLTO decreases by
about 7% for no-op incremental builds or about 1% for full builds. Total
bitcode file size decreases by about 3%.

As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2017-April/111732.html

Differential Revision: https://reviews.llvm.org/D31838

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300464 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-17 17:51:36 +00:00

25 lines
817 B
LLVM

; Verify that auto-upgrading intrinsics works with Lazy loaded bitcode
; Do setup work for all below tests: generate bitcode and combined index
; RUN: opt -module-summary %s -o %t.bc
; RUN: llvm-lto -thinlto-action=thinlink -o %t3.bc %t.bc %p/Inputs/autoupgrade.bc
; We can't use llvm-dis here, because it would do the autoupgrade itself.
; RUN: llvm-link -summary-index=%t3.bc \
; RUN: -import=globalfunc1:%p/Inputs/autoupgrade.bc %t.bc \
; RUN: | llvm-bcanalyzer -dump | FileCheck %s
; CHECK: <STRTAB_BLOCK
; CHECK-NEXT: blob data = 'mainglobalfunc1llvm.invariant.start.p0i8'
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.11.0"
define i32 @main() #0 {
entry:
call void (...) @globalfunc1()
ret i32 0
}
declare void @globalfunc1(...) #1