[AArch64, ARM] Enable GlobalMerge with -O3 rather than -O1.

The pass used to be enabled by default with CodeGenOpt::Less (-O1).
This is too aggressive, considering the pass indiscriminately merges
all globals together.

Currently, performance doesn't always improve, and, on code that uses
few globals (e.g., the odd file- or function- static), more often than
not is degraded by the optimization.  Lengthy discussion can be found
on llvmdev (AArch64-focused;  ARM has similar problems):
  http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-February/082800.html
Also, it makes tooling and debuggers less useful when dealing with
globals and data sections.

GlobalMerge needs to better identify those cases that benefit, and this
will be done separately.  In the meantime, move the pass to run with
-O3 rather than -O1, on both ARM and AArch64.

llvm-svn: 233024

11 files changed, 25 insertions, 24 deletions

diff --git a/llvm/test/CodeGen/AArch64/global-merge-1.ll b/llvm/test/CodeGen/AArch64/global-merge-1.ll
index 7dc8da1c444..b40438900ab 100644
--- a/llvm/test/CodeGen/AArch64/global-merge-1.ll
+++ b/llvm/test/CodeGen/AArch64/global-merge-1.ll
@@ -1,11 +1,11 @@
-; RUN: llc %s -mtriple=aarch64-none-linux-gnu -enable-global-merge -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-none-linux-gnu -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-none-linux-gnu -O3 -enable-global-merge -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-none-linux-gnu -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
 
-; RUN: llc %s -mtriple=aarch64-linux-gnuabi -enable-global-merge -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-linux-gnuabi -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-linux-gnuabi -O3 -enable-global-merge -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-linux-gnuabi -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
 
-; RUN: llc %s -mtriple=aarch64-apple-ios -enable-global-merge -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
-; RUN: llc %s -mtriple=aarch64-apple-ios -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
+; RUN: llc %s -mtriple=aarch64-apple-ios -O3 -enable-global-merge -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
+; RUN: llc %s -mtriple=aarch64-apple-ios -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
 
 @m = internal global i32 0, align 4
 @n = internal global i32 0, align 4
diff --git a/llvm/test/CodeGen/AArch64/global-merge-2.ll b/llvm/test/CodeGen/AArch64/global-merge-2.ll
index 70b700c7e57..d5967b93831 100644
--- a/llvm/test/CodeGen/AArch64/global-merge-2.ll
+++ b/llvm/test/CodeGen/AArch64/global-merge-2.ll
@@ -1,6 +1,6 @@
-; RUN: llc %s -mtriple=aarch64-none-linux-gnu -enable-global-merge -global-merge-on-external -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-linux-gnuabi -enable-global-merge -global-merge-on-external -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-apple-ios -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
+; RUN: llc %s -mtriple=aarch64-none-linux-gnu -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-linux-gnuabi -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-apple-ios -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
 
 @x = global i32 0, align 4
 @y = global i32 0, align 4
diff --git a/llvm/test/CodeGen/AArch64/global-merge-3.ll b/llvm/test/CodeGen/AArch64/global-merge-3.ll
index 2364d8de588..15035c0032e 100644
--- a/llvm/test/CodeGen/AArch64/global-merge-3.ll
+++ b/llvm/test/CodeGen/AArch64/global-merge-3.ll
@@ -1,6 +1,6 @@
-; RUN: llc %s -mtriple=aarch64-none-linux-gnu -enable-global-merge -global-merge-on-external -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-linux-gnuabi -enable-global-merge -global-merge-on-external -o - | FileCheck %s
-; RUN: llc %s -mtriple=aarch64-apple-ios -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
+; RUN: llc %s -mtriple=aarch64-none-linux-gnu -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-linux-gnuabi -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-apple-ios -O3 -enable-global-merge -global-merge-on-external -o - | FileCheck %s --check-prefix=CHECK-APPLE-IOS
 
 @x = global [1000 x i32] zeroinitializer, align 1
 @y = global [1000 x i32] zeroinitializer, align 1
diff --git a/llvm/test/CodeGen/AArch64/global-merge-4.ll b/llvm/test/CodeGen/AArch64/global-merge-4.ll
index d3ae32d3b5c..8fb7747977c 100644
--- a/llvm/test/CodeGen/AArch64/global-merge-4.ll
+++ b/llvm/test/CodeGen/AArch64/global-merge-4.ll
@@ -1,4 +1,4 @@
-; RUN: llc %s -mtriple=aarch64-linux-gnuabi -enable-global-merge -o - | FileCheck %s
+; RUN: llc %s -mtriple=aarch64-linux-gnuabi -O3 -enable-global-merge -o - | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32:64-S128"
 target triple = "arm64-apple-ios7.0.0"
diff --git a/llvm/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll b/llvm/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll
index 8db166afec6..d3c0feeab45 100644
--- a/llvm/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll
+++ b/llvm/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll
@@ -1,6 +1,6 @@
-; RUN: llc  %s -mtriple=armv7-linux-gnueabi -filetype=obj -o - | \
+; RUN: llc  %s -mtriple=armv7-linux-gnueabi -O3 -filetype=obj -o - | \
 ; RUN:    llvm-readobj -s -t | FileCheck  -check-prefix=OBJ %s
-; RUN: llc  %s -mtriple=armv7-linux-gnueabi -o - | \
+; RUN: llc  %s -mtriple=armv7-linux-gnueabi -O3 -o - | \
 ; RUN:    FileCheck  -check-prefix=ASM %s
 
 
diff --git a/llvm/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll b/llvm/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll
index b361c13941c..7196d2d37bd 100644
--- a/llvm/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll
+++ b/llvm/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll
@@ -1,4 +1,4 @@
-; RUN: llc -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: llc -O3 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32"
 target triple = "thumbv7-apple-darwin10"
diff --git a/llvm/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll b/llvm/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll
index 091d037356d..236dc1c0dbc 100644
--- a/llvm/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll
+++ b/llvm/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumbv7-apple-darwin10 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin10 -O3 | FileCheck %s
 ; CHECK: .zerofill __DATA,__bss,__MergedGlobals,16,2
 
 @prev = external global [0 x i16]
diff --git a/llvm/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll b/llvm/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll
index dee4d67ec54..1614e8d0c67 100644
--- a/llvm/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll
+++ b/llvm/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll
@@ -1,4 +1,4 @@
-; RUN: llc -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+; RUN: llc -O3 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
 
 ; Check debug info output for merged global.
 ; DW_AT_location
diff --git a/llvm/test/CodeGen/ARM/global-merge-1.ll b/llvm/test/CodeGen/ARM/global-merge-1.ll
index 5db4b0086ec..03a9d33c887 100644
--- a/llvm/test/CodeGen/ARM/global-merge-1.ll
+++ b/llvm/test/CodeGen/ARM/global-merge-1.ll
@@ -1,9 +1,10 @@
 ; RUN: llc %s -O0 -o - | FileCheck -check-prefix=NO-MERGE %s
-; RUN: llc %s -O0 -o - -enable-global-merge=false | FileCheck -check-prefix=NO-MERGE %s
-; RUN: llc %s -O0 -o - -enable-global-merge=true | FileCheck -check-prefix=NO-MERGE %s
-; RUN: llc %s -O1 -o - | FileCheck -check-prefix=MERGE %s
+; RUN: llc %s -O1 -o - | FileCheck -check-prefix=NO-MERGE %s
 ; RUN: llc %s -O1 -o - -enable-global-merge=false | FileCheck -check-prefix=NO-MERGE %s
-; RUN: llc %s -O1 -o - -enable-global-merge=true | FileCheck -check-prefix=MERGE %s
+; RUN: llc %s -O1 -o - -enable-global-merge=true | FileCheck -check-prefix=NO-MERGE %s
+; RUN: llc %s -O3 -o - | FileCheck -check-prefix=MERGE %s
+; RUN: llc %s -O3 -o - -enable-global-merge=false | FileCheck -check-prefix=NO-MERGE %s
+; RUN: llc %s -O3 -o - -enable-global-merge=true | FileCheck -check-prefix=MERGE %s
 
 ; MERGE-NOT: .zerofill __DATA,__bss,_bar,20,2
 ; MERGE-NOT: .zerofill __DATA,__bss,_baz,20,2
diff --git a/llvm/test/CodeGen/ARM/global-merge-addrspace.ll b/llvm/test/CodeGen/ARM/global-merge-addrspace.ll
index 0efa690bde2..7b71e89bbe7 100644
--- a/llvm/test/CodeGen/ARM/global-merge-addrspace.ll
+++ b/llvm/test/CodeGen/ARM/global-merge-addrspace.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumb-apple-darwin | FileCheck %s
+; RUN: llc < %s -mtriple=thumb-apple-darwin -O3 | FileCheck %s
 ; Test the GlobalMerge pass. Check that the pass does not crash when using
 ; multiple address spaces.
 
diff --git a/llvm/test/CodeGen/ARM/global-merge.ll b/llvm/test/CodeGen/ARM/global-merge.ll
index f88e9279619..d535ea7c0ce 100644
--- a/llvm/test/CodeGen/ARM/global-merge.ll
+++ b/llvm/test/CodeGen/ARM/global-merge.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=thumb-apple-darwin -global-merge-on-const=true | FileCheck %s
+; RUN: llc < %s -mtriple=thumb-apple-darwin -O3 -global-merge-on-const=true | FileCheck %s
 ; Test the ARMGlobalMerge pass.  Use -march=thumb because it has a small
 ; value for the maximum offset (127).