Evict local live ranges if they can be reassigned.

The previous change to local live range allocation also suppressed
eviction of local ranges. In rare cases, this could result in more
expensive register choices. This commit actually revives a feature
that I added long ago: check if live ranges can be reassigned before
eviction. But now it only happens in rare cases of evicting a local
live range because another local live range wants a cheaper register.

The benefit is improved code size for some benchmarks on x86 and armv7.

I measured no significant compile time increase and performance
changes are noise.

llvm-svn: 187140

4 files changed, 6 insertions, 12 deletions

diff --git a/llvm/test/CodeGen/ARM/avoid-cpsr-rmw.ll b/llvm/test/CodeGen/ARM/avoid-cpsr-rmw.ll
index 13d8da67a53..0217a4a8fb8 100644
--- a/llvm/test/CodeGen/ARM/avoid-cpsr-rmw.ll
+++ b/llvm/test/CodeGen/ARM/avoid-cpsr-rmw.ll
@@ -1,7 +1,5 @@
-; RUN: true
-; Disabled for a single commit only.
-; disabled: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a9 | FileCheck %s
-; disabled: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=swift     | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=cortex-a9 | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mcpu=swift     | FileCheck %s
 ; Avoid some 's' 16-bit instruction which partially update CPSR (and add false
 ; dependency) when it isn't dependent on last CPSR defining instruction.
 ; rdar://8928208
diff --git a/llvm/test/CodeGen/X86/StackColoring.ll b/llvm/test/CodeGen/X86/StackColoring.ll
index fd2ad91dd6f..f1d92965c49 100644
--- a/llvm/test/CodeGen/X86/StackColoring.ll
+++ b/llvm/test/CodeGen/X86/StackColoring.ll
@@ -1,7 +1,5 @@
-; RUN: true
-; Disabled for a single commit only
-; disabled: llc -mcpu=corei7 -no-stack-coloring=false < %s | FileCheck %s --check-prefix=YESCOLOR
-; disabled: llc -mcpu=corei7 -no-stack-coloring=true  < %s | FileCheck %s --check-prefix=NOCOLOR
+; RUN: llc -mcpu=corei7 -no-stack-coloring=false < %s | FileCheck %s --check-prefix=YESCOLOR
+; RUN: llc -mcpu=corei7 -no-stack-coloring=true  < %s | FileCheck %s --check-prefix=NOCOLOR
 
 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-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.8.0"
diff --git a/llvm/test/CodeGen/X86/legalize-shift-64.ll b/llvm/test/CodeGen/X86/legalize-shift-64.ll
index 3cdd49412a8..77364688afe 100644
--- a/llvm/test/CodeGen/X86/legalize-shift-64.ll
+++ b/llvm/test/CodeGen/X86/legalize-shift-64.ll
@@ -1,6 +1,4 @@
-; RUN: true
-; disabled: llc -mcpu=generic -mtriple=i686-unknown-unknown < %s | FileCheck %s
-; Disabled for a single commit only.
+; RUN: llc -mcpu=generic -mtriple=i686-unknown-unknown < %s | FileCheck %s
 define i64 @test1(i32 %xx, i32 %test) nounwind {
   %conv = zext i32 %xx to i64
   %and = and i32 %test, 7
diff --git a/llvm/test/CodeGen/X86/misched-matmul.ll b/llvm/test/CodeGen/X86/misched-matmul.ll
index 7fd78824e78..6b676071152 100644
--- a/llvm/test/CodeGen/X86/misched-matmul.ll
+++ b/llvm/test/CodeGen/X86/misched-matmul.ll
@@ -7,7 +7,7 @@
 ; flag to disable it for this test case.
 ;
 ; CHECK: @wrap_mul4
-; CHECK: 21 regalloc - Number of spills inserted
+; CHECK: 22 regalloc - Number of spills inserted
 
 define void @wrap_mul4(double* nocapture %Out, [4 x double]* nocapture %A, [4 x double]* nocapture %B) #0 {
 entry: