[AArch64][GlobalISel] Enable the localizer for optimized builds.

Despite the fact that the localizer's original motivation was to fix horrendous
constant spilling at -O0, shortening live ranges still has net benefits even
with optimizations enabled.

On an -Os build of CTMark, doing this improves code size by 0.5% geomean.

There are a few regressions, bullet increasing in size by 0.5%. One example from
bullet where code size increased slightly was due to GlobalISel actually now
generating the same code as SelectionDAG. So we actually have an opportunity
in future to implement better heuristics for localization and therefore be
*better* than SDAG in some cases. In relation to other optimizations though that
one is relatively minor.

Differential Revision: https://reviews.llvm.org/D67303

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371266 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AArch64/AArch64TargetMachine.cpp b/lib/Target/AArch64/AArch64TargetMachine.cpp
index 227d023400e9721d998b070ccf249df6836f3292..c3a8ace304a59770a3096c497548ae521d0373a4 100644 (file)
--- a/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -518,9 +518,7 @@ bool AArch64PassConfig::addRegBankSelect() {
 }
 
 void AArch64PassConfig::addPreGlobalInstructionSelect() {
-  // Workaround the deficiency of the fast register allocator.
-  if (TM->getOptLevel() == CodeGenOpt::None)
-    addPass(new Localizer());
+  addPass(new Localizer());
 }
 
 bool AArch64PassConfig::addGlobalInstructionSelect() {

diff --git a/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll b/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
index fd7809fa0c168e3c6f2464450e811754a03c7a3f..b7588d0447f26b98f948960435d19e23ddd5474f 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
+++ b/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
@@ -51,7 +51,7 @@
 ; VERIFY-NEXT:   Verify generated machine code
 ; ENABLED-NEXT:  RegBankSelect
 ; VERIFY-NEXT:   Verify generated machine code
-; ENABLED-O0-NEXT:  Localizer
+; ENABLED-NEXT:  Localizer
 ; VERIFY-O0-NEXT:   Verify generated machine code
 ; ENABLED-NEXT: Analysis for ComputingKnownBits
 ; ENABLED-NEXT:  InstructionSelect

diff --git a/test/CodeGen/AArch64/GlobalISel/localizer-in-O0-pipeline.mir b/test/CodeGen/AArch64/GlobalISel/localizer-in-O0-pipeline.mir
index 5d4dad6916649d913a4a236d7326dee7cd0b5a17..869b328a7521fca45989b261aa291e27fbe61a97 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/localizer-in-O0-pipeline.mir
+++ b/test/CodeGen/AArch64/GlobalISel/localizer-in-O0-pipeline.mir
@@ -60,18 +60,18 @@ registers:
 
 # Second block will get the constant 1.0 when the localizer is enabled.
 # CHECK: bb.1.{{[a-zA-Z0-9]+}}:
-# OPT-NOT: G_FCONSTANT
+# OPT: [[FONE:%[0-9]+]]:fpr(s32) = G_FCONSTANT float 1.000000e+00
 # OPTNONE: [[FONE:%[0-9]+]]:fpr(s32) = G_FCONSTANT float 1.000000e+00
 # CHECK: G_BR %bb.3
 
 # Thrid block will get the constant 2.0 when the localizer is enabled.
 # CHECK: bb.2.{{[a-zA-Z0-9]+}}:
-# OPT-NOT: G_FCONSTANT
+# OPT: [[FTWO:%[0-9]+]]:fpr(s32) = G_FCONSTANT float 2.000000e+00
 # OPTNONE: [[FTWO:%[0-9]+]]:fpr(s32) = G_FCONSTANT float 2.000000e+00
 
 # CHECK: bb.3.end
 # OPTNONE: %2:fpr(s32) = PHI [[FONE]](s32), %bb.1, [[FTWO]](s32), %bb.2
-# OPT: %2:fpr(s32) = PHI %4(s32), %bb.1, %5(s32), %bb.2
+# OPT: %2:fpr(s32) = PHI [[FONE]](s32), %bb.1, [[FTWO]](s32), %bb.2
 # CHECK-NEXT: G_FADD %0, %2
 body:             |
   bb.0 (%ir-block.0):

diff --git a/test/CodeGen/AArch64/GlobalISel/swifterror.ll b/test/CodeGen/AArch64/GlobalISel/swifterror.ll
index 7a4184ca4e9bfddc59e97fe32671bfbe9cb5f1c9..8e0c287725a0e023aadb24057934263553f220b7 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/swifterror.ll
+++ b/test/CodeGen/AArch64/GlobalISel/swifterror.ll
@@ -98,9 +98,9 @@ handler:
 define float @foo_if(%swift_error** swifterror %error_ptr_ref, i32 %cc) {
 ; CHECK-LABEL: foo_if:
 ; CHECK: cbz w0
-; CHECK: mov [[ID:w[0-9]+]], #1
 ; CHECK: mov w0, #16
 ; CHECK: malloc
+; CHECK: mov [[ID:w[0-9]+]], #1
 ; CHECK: strb [[ID]], [x0, #8]
 ; CHECK: mov x21, x0
 ; CHECK-NOT: x21