[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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233024 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AArch64/AArch64TargetMachine.cpp b/lib/Target/AArch64/AArch64TargetMachine.cpp
index 187d2ce..f902f64 100644 (file)
--- a/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -245,7 +245,7 @@ bool AArch64PassConfig::addPreISel() {
   // FIXME: On AArch64, this depends on the type.
   // Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
   // and the offset has to be a multiple of the related size in bytes.
-  if (TM->getOptLevel() != CodeGenOpt::None)
+  if (TM->getOptLevel() == CodeGenOpt::Aggressive)
     addPass(createGlobalMergePass(TM, 4095));
   if (TM->getOptLevel() != CodeGenOpt::None)
     addPass(createAArch64AddressTypePromotionPass());

diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index 4586a9f..fcb96e0 100644 (file)
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -327,7 +327,7 @@ void ARMPassConfig::addIRPasses() {
 }
 
 bool ARMPassConfig::addPreISel() {
-  if (TM->getOptLevel() != CodeGenOpt::None)
+  if (TM->getOptLevel() == CodeGenOpt::Aggressive)
     // FIXME: This is using the thumb1 only constant value for
     // maximal global offset for merging globals. We may want
     // to look into using the old value for non-thumb1 code of

diff --git a/test/CodeGen/AArch64/global-merge-1.ll b/test/CodeGen/AArch64/global-merge-1.ll
index 7dc8da1..b404389 100644 (file)
--- a/test/CodeGen/AArch64/global-merge-1.ll
+++ b/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/test/CodeGen/AArch64/global-merge-2.ll b/test/CodeGen/AArch64/global-merge-2.ll
index 70b700c..d5967b9 100644 (file)
--- a/test/CodeGen/AArch64/global-merge-2.ll
+++ b/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/test/CodeGen/AArch64/global-merge-3.ll b/test/CodeGen/AArch64/global-merge-3.ll
index 2364d8d..15035c0 100644 (file)
--- a/test/CodeGen/AArch64/global-merge-3.ll
+++ b/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/test/CodeGen/AArch64/global-merge-4.ll b/test/CodeGen/AArch64/global-merge-4.ll
index d3ae32d..8fb7747 100644 (file)
--- a/test/CodeGen/AArch64/global-merge-4.ll
+++ b/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/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll b/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll
index 8db166a..d3c0fee 100644 (file)
--- a/test/CodeGen/ARM/2010-12-15-elf-lcomm.ll
+++ b/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/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll b/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll
index b361c13..7196d2d 100644 (file)
--- a/test/CodeGen/ARM/2011-01-19-MergedGlobalDbg.ll
+++ b/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/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll b/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll
index 091d037..236dc1c 100644 (file)
--- a/test/CodeGen/ARM/2011-06-29-MergeGlobalsAlign.ll
+++ b/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/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll b/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll
index dee4d67..1614e8d 100644 (file)
--- a/test/CodeGen/ARM/2011-08-02-MergedGlobalDbg.ll
+++ b/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/test/CodeGen/ARM/global-merge-1.ll b/test/CodeGen/ARM/global-merge-1.ll
index 5db4b00..03a9d33 100644 (file)
--- a/test/CodeGen/ARM/global-merge-1.ll
+++ b/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/test/CodeGen/ARM/global-merge-addrspace.ll b/test/CodeGen/ARM/global-merge-addrspace.ll
index 0efa690..7b71e89 100644 (file)
--- a/test/CodeGen/ARM/global-merge-addrspace.ll
+++ b/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/test/CodeGen/ARM/global-merge.ll b/test/CodeGen/ARM/global-merge.ll
index f88e927..d535ea7 100644 (file)
--- a/test/CodeGen/ARM/global-merge.ll
+++ b/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).