llvm-mirror/test/ThinLTO/X86/index-const-prop2.ll
Teresa Johnson cacc24d853 [ThinLTO] Fix importing of writeonly variables in distributed ThinLTO
Summary:
D69561/dde5893 enabled importing of readonly variables with references,
however, it introduced a bug relating to importing/internalization of
writeonly variables with references.

A fix for this was added in D70006/7f92d66. But this didn't work in
distributed ThinLTO mode. The reason is that the fix (importing the
writeonly var with a zeroinitializer) was only applied when there were
references on the writeonly var summary. In distributed ThinLTO mode,
where we only have a small slice of the index, we will not have the
references on the importing side if we are not importing those
referenced values. Rather than changing this handshaking (which will
require a lot of other changes, since that's how we know what to import
in the distributed backend clang invocation), we can simply always give
the writeonly variable a zero initializer.

Reviewers: evgeny777, steven_wu

Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70977
2019-12-04 14:59:27 -08:00

106 lines
3.7 KiB
LLVM

; Check constant propagation in thinlto combined summary. This allows us to do 2 things:
; 1. Internalize global definition which is not used externally if all accesses to it are read-only
; 2. Make a local copy of internal definition if all accesses to it are readonly. This allows constant
; folding it during optimziation phase.
; RUN: opt -module-summary %s -o %t1.bc
; RUN: opt -module-summary %p/Inputs/index-const-prop.ll -o %t2.bc
; RUN: llvm-lto2 run %t1.bc %t2.bc -save-temps \
; RUN: -r=%t2.bc,foo,pl \
; RUN: -r=%t2.bc,bar,pl \
; RUN: -r=%t2.bc,baz,pl \
; RUN: -r=%t2.bc,rand, \
; RUN: -r=%t2.bc,gBar,pl \
; RUN: -r=%t1.bc,main,plx \
; RUN: -r=%t1.bc,main2,pl \
; RUN: -r=%t1.bc,foo, \
; RUN: -r=%t1.bc,bar, \
; RUN: -r=%t1.bc,baz, \
; RUN: -r=%t1.bc,gBar, \
; RUN: -o %t3
; RUN: llvm-dis %t3.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT
; RUN: llvm-dis %t3.1.5.precodegen.bc -o - | FileCheck %s --check-prefix=CODEGEN
; Now check that we won't internalize global (gBar) if it's externally referenced
; RUN: llvm-lto2 run %t1.bc %t2.bc -save-temps \
; RUN: -r=%t2.bc,foo,pl \
; RUN: -r=%t2.bc,bar,pl \
; RUN: -r=%t2.bc,baz,pl \
; RUN: -r=%t2.bc,rand, \
; RUN: -r=%t2.bc,gBar,plx \
; RUN: -r=%t1.bc,main,plx \
; RUN: -r=%t1.bc,main2,pl \
; RUN: -r=%t1.bc,foo, \
; RUN: -r=%t1.bc,bar, \
; RUN: -r=%t1.bc,baz, \
; RUN: -r=%t1.bc,gBar, \
; RUN: -o %t4
; RUN: llvm-dis %t4.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT2
; Run again but with main2 exported instead of main to check that write only
; variables are optimized out.
; RUN: llvm-lto2 run %t1.bc %t2.bc -save-temps \
; RUN: -r=%t2.bc,foo,pl \
; RUN: -r=%t2.bc,bar,pl \
; RUN: -r=%t2.bc,baz,pl \
; RUN: -r=%t2.bc,rand, \
; RUN: -r=%t2.bc,gBar,pl \
; RUN: -r=%t1.bc,main,pl \
; RUN: -r=%t1.bc,main2,plx \
; RUN: -r=%t1.bc,foo, \
; RUN: -r=%t1.bc,bar, \
; RUN: -r=%t1.bc,baz, \
; RUN: -r=%t1.bc,gBar, \
; RUN: -o %t5
; RUN: llvm-dis %t5.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT-WRITEONLY
; RUN: llvm-dis %t5.1.5.precodegen.bc -o - | FileCheck %s --check-prefix=CODEGEN2
; Check that gFoo and gBar were eliminated from source module together
; with corresponsing stores
; RUN: llvm-dis %t5.2.5.precodegen.bc -o - | FileCheck %s --check-prefix=CODEGEN2-SRC
; IMPORT: @gFoo.llvm.0 = internal unnamed_addr global i32 1, align 4
; IMPORT-NEXT: @gBar = internal local_unnamed_addr global i32 2, align 4
; IMPORT: !DICompileUnit({{.*}})
; Write only variables are imported with a zero initializer.
; IMPORT-WRITEONLY: @gFoo.llvm.0 = internal unnamed_addr global i32 0
; IMPORT-WRITEONLY: @gBar = internal local_unnamed_addr global i32 0
; CODEGEN: i32 @main()
; CODEGEN-NEXT: ret i32 3
; IMPORT2: @gBar = available_externally dso_local local_unnamed_addr global i32 2, align 4
; CODEGEN2: i32 @main2
; CODEGEN2-NEXT: %1 = tail call i32 @rand()
; CODEGEN2-NEXT: %2 = tail call i32 @rand()
; CODEGEN2-NEXT: ret i32 0
; CODEGEN2-SRC: void @baz()
; CODEGEN2-SRC-NEXT: %1 = tail call i32 @rand()
; CODEGEN2-SRC-NEXT: %2 = tail call i32 @rand()
; CODEGEN2-SRC-NEXT: ret void
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
; We should be able to link external definition of gBar to its declaration
@gBar = external global i32
define i32 @main() local_unnamed_addr {
%call = tail call i32 bitcast (i32 (...)* @foo to i32 ()*)()
%call1 = tail call i32 bitcast (i32 (...)* @bar to i32 ()*)()
%add = add nsw i32 %call1, %call
ret i32 %add
}
define i32 @main2() local_unnamed_addr {
tail call void @baz()
ret i32 0
}
declare i32 @foo(...) local_unnamed_addr
declare i32 @bar(...) local_unnamed_addr
declare void @baz() local_unnamed_addr