Loop unroller: set thresholds for optsize and minsize functions to zero

Before r268509, Clang would disable the loop unroll pass when optimizing
for size. That commit enabled it to be able to support unroll pragmas
in -Os builds. However, this regressed binary size in one of Chromium's
DLLs with ~100 KB.

This restores the original behaviour of no unrolling at -Os, but doing it
in LLVM instead of Clang makes more sense, and also allows the pragmas to
keep working.

Differential revision: http://reviews.llvm.org/D20115

llvm-svn: 269124

1 files changed, 13 insertions, 43 deletions

diff --git a/llvm/test/Transforms/LoopUnroll/unroll-opt-attribute.ll b/llvm/test/Transforms/LoopUnroll/unroll-opt-attribute.ll
index 334162f5605..f4a76c71368 100644
--- a/llvm/test/Transforms/LoopUnroll/unroll-opt-attribute.ll
+++ b/llvm/test/Transforms/LoopUnroll/unroll-opt-attribute.ll
@@ -4,10 +4,10 @@
 

 ;///////////////////// TEST 1 //////////////////////////////

 

-; This test shows that with optsize attribute, the loop is unrolled

-; according to the specified unroll factor.

+; This test shows that the loop is unrolled according to the specified

+; unroll factor.

 

-define void @Test1() nounwind optsize {

+define void @Test1() nounwind {

 entry:

   br label %loop

 

@@ -32,38 +32,10 @@ exit:
 

 ;///////////////////// TEST 2 //////////////////////////////

 

-; This test shows that with minsize attribute, the loop is unrolled

-; according to the specified unroll factor.

-

-define void @Test2() nounwind minsize {

-entry:

-  br label %loop

-

-loop:

-  %iv = phi i32 [ 0, %entry ], [ %inc, %loop ]

-  %inc = add i32 %iv, 1

-  %exitcnd = icmp uge i32 %inc, 1024

-  br i1 %exitcnd, label %exit, label %loop

-

-exit:

-  ret void

-}

-

-; CHECK_COUNT4-LABEL: @Test2

-; CHECK_COUNT4:      phi

-; CHECK_COUNT4-NEXT: add

-; CHECK_COUNT4-NEXT: add

-; CHECK_COUNT4-NEXT: add

-; CHECK_COUNT4-NEXT: add

-; CHECK_COUNT4-NEXT: icmp

-

-

-;///////////////////// TEST 3 //////////////////////////////

-

 ; This test shows that with optnone attribute, the loop is not unrolled

 ; even if an unroll factor was specified.

 

-define void @Test3() nounwind optnone noinline {

+define void @Test2() nounwind optnone noinline {

 entry:

   br label %loop

 

@@ -77,20 +49,19 @@ exit:
   ret void

 }

 

-; CHECK_COUNT4-LABEL: @Test3

+; CHECK_COUNT4-LABEL: @Test2

 ; CHECK_COUNT4:      phi

 ; CHECK_COUNT4-NEXT: add

 ; CHECK_COUNT4-NEXT: icmp

 

 

-;///////////////////// TEST 4 //////////////////////////////

+;///////////////////// TEST 3 //////////////////////////////

 

-; This test shows that without any attribute, this loop is fully unrolled 

-; by default.

+; This test shows that this loop is fully unrolled by default.

 

 @tab = common global [24 x i32] zeroinitializer, align 4

 

-define i32 @Test4() {

+define i32 @Test3() {

 entry:

   br label %for.body

 

@@ -106,7 +77,7 @@ for.end:                                          ; preds = %for.body
   ret i32 42

 }

 

-; CHECK_NOCOUNT-LABEL: @Test4

+; CHECK_NOCOUNT-LABEL: @Test3

 ; CHECK_NOCOUNT:      store

 ; CHECK_NOCOUNT-NEXT: store

 ; CHECK_NOCOUNT-NEXT: store

@@ -134,12 +105,11 @@ for.end:                                          ; preds = %for.body
 ; CHECK_NOCOUNT-NEXT: ret

 

 

-;///////////////////// TEST 5 //////////////////////////////

+;///////////////////// TEST 4 //////////////////////////////

 

-; This test shows that with optsize attribute, this loop is not unrolled 

-; by default.

+; This test shows that with optsize attribute, this loop is not unrolled.

 

-define i32 @Test5() optsize {

+define i32 @Test4() optsize {

 entry:

   br label %for.body

 

@@ -155,6 +125,6 @@ for.end:                                          ; preds = %for.body
   ret i32 42

 }

 

-; CHECK_NOCOUNT-LABEL: @Test5

+; CHECK_NOCOUNT-LABEL: @Test4

 ; CHECK_NOCOUNT:      phi

 ; CHECK_NOCOUNT:      icmp