Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.

(This is the second attempt to submit this patch. The first caused two assertion
 failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)

The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254377

5 files changed, 16 insertions, 16 deletions

diff --git a/llvm/test/CodeGen/ARM/ifcvt-branch-weight-bug.ll b/llvm/test/CodeGen/ARM/ifcvt-branch-weight-bug.ll
index e17da7a9720..a44c9721d6c 100644
--- a/llvm/test/CodeGen/ARM/ifcvt-branch-weight-bug.ll
+++ b/llvm/test/CodeGen/ARM/ifcvt-branch-weight-bug.ll
@@ -14,15 +14,15 @@ entry:
   br i1 undef, label %for.end, label %for.body
 
 ; Before if conversion, we have
-; for.body -> lor.lhs.false.i (62)
-;          -> for.cond.backedge (62)
-; lor.lhs.false.i -> for.cond.backedge (1048575)
-;                 -> cond.false.i (1)
+; for.body -> lor.lhs.false.i (50%)
+;          -> for.cond.backedge (50%)
+; lor.lhs.false.i -> for.cond.backedge (100%)
+;                 -> cond.false.i (0%)
 ; Afer if conversion, we have
-; for.body -> for.cond.backedge (130023362)
-;          -> cond.false.i (62)
+; for.body -> for.cond.backedge (100%)
+;          -> cond.false.i (0%)
 ; CHECK: BB#1: derived from LLVM BB %for.body
-; CHECK: Successors according to CFG: BB#2(4294967291) BB#4(2048)
+; CHECK: Successors according to CFG: BB#2(0x7ffffc00 / 0x80000000 = 100.00%) BB#4(0x00000400 / 0x80000000 = 0.00%)
 for.body:
   br i1 undef, label %for.cond.backedge, label %lor.lhs.false.i, !prof !1
 
diff --git a/llvm/test/CodeGen/ARM/ifcvt-branch-weight.ll b/llvm/test/CodeGen/ARM/ifcvt-branch-weight.ll
index f2a1229d0d8..0de039cde23 100644
--- a/llvm/test/CodeGen/ARM/ifcvt-branch-weight.ll
+++ b/llvm/test/CodeGen/ARM/ifcvt-branch-weight.ll
@@ -19,7 +19,7 @@ bb:
   br i1 %9, label %return, label %bb2
 
 ; CHECK: BB#2: derived from LLVM BB %bb2
-; CHECK: Successors according to CFG: BB#3(4294967289) BB#4(4294967287)
+; CHECK: Successors according to CFG: BB#3({{[0-9a-fx/= ]+}}50.00%) BB#4({{[0-9a-fx/= ]+}}50.00%)
 
 bb2:
   %v10 = icmp eq i32 %3, 16
diff --git a/llvm/test/CodeGen/ARM/ifcvt-iter-indbr.ll b/llvm/test/CodeGen/ARM/ifcvt-iter-indbr.ll
index 6ce9bcb56ef..a96b6e8a1e8 100644
--- a/llvm/test/CodeGen/ARM/ifcvt-iter-indbr.ll
+++ b/llvm/test/CodeGen/ARM/ifcvt-iter-indbr.ll
@@ -1,5 +1,5 @@
 ; RUN: llc < %s -mtriple thumbv7s-apple-darwin  -asm-verbose=false | FileCheck %s
-; RUN: llc < %s -mtriple thumbv7s-apple-darwin  -asm-verbose=false -print-machineinstrs=if-converter 2>&1 | FileCheck --check-prefix=CHECK-WEIGHT %s
+; RUN: llc < %s -mtriple thumbv7s-apple-darwin  -asm-verbose=false -print-machineinstrs=if-converter 2>&1 | FileCheck --check-prefix=CHECK-PROB %s
 
 declare i32 @foo(i32)
 declare i8* @bar(i32, i8*, i8*)
@@ -29,10 +29,10 @@ declare i8* @bar(i32, i8*, i8*)
 ; CHECK-NEXT: [[FOOCALL]]:
 ; CHECK-NEXT:  blx _foo
 ;
-; CHECK-WEIGHT: BB#0:
-; CHECK-WEIGHT: Successors according to CFG: BB#1(1073741824) BB#2(536870912) BB#4(536870912)
-; CHECK-WEIGHT: BB#1:
-; CHECK-WEIGHT: Successors according to CFG: BB#2(1610612736) BB#4(536870912)
+; CHECK-PROB: BB#0:
+; CHECK-PROB: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}50.00%) BB#2({{[0-9a-fx/= ]+}}25.00%) BB#4({{[0-9a-fx/= ]+}}25.00%)
+; CHECK-PROB: BB#1:
+; CHECK-PROB: Successors according to CFG: BB#2({{[0-9a-fx/= ]+}}75.00%) BB#4({{[0-9a-fx/= ]+}}25.00%)
 
 define i32 @test(i32 %a, i32 %a2, i32* %p, i32* %p2) {
 entry:
diff --git a/llvm/test/CodeGen/ARM/tail-merge-branch-weight.ll b/llvm/test/CodeGen/ARM/tail-merge-branch-weight.ll
index 95b0a202e7f..f83f2881579 100644
--- a/llvm/test/CodeGen/ARM/tail-merge-branch-weight.ll
+++ b/llvm/test/CodeGen/ARM/tail-merge-branch-weight.ll
@@ -9,7 +9,7 @@
 ;                = 0.2 * 0.4 + 0.8 * 0.7 = 0.64
 
 ; CHECK: # Machine code for function test0:
-; CHECK: Successors according to CFG: BB#{{[0-9]+}}(13) BB#{{[0-9]+}}(24)
+; CHECK: Successors according to CFG: BB#{{[0-9]+}}({{[0-9a-fx/= ]+}}20.00%) BB#{{[0-9]+}}({{[0-9a-fx/= ]+}}80.00%)
 ; CHECK: BB#{{[0-9]+}}:
 ; CHECK: BB#{{[0-9]+}}:
 ; CHECK: # End machine code for function test0.
diff --git a/llvm/test/CodeGen/ARM/taildup-branch-weight.ll b/llvm/test/CodeGen/ARM/taildup-branch-weight.ll
index 576c120b444..799ef62416e 100644
--- a/llvm/test/CodeGen/ARM/taildup-branch-weight.ll
+++ b/llvm/test/CodeGen/ARM/taildup-branch-weight.ll
@@ -3,7 +3,7 @@
 ; RUN:	| FileCheck %s
 
 ; CHECK: Machine code for function test0:
-; CHECK: Successors according to CFG: BB#1(67108864) BB#2(2080374784)
+; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}3.12%) BB#2({{[0-9a-fx/= ]+}}96.88%)
 
 define void @test0(i32 %a, i32 %b, i32* %c, i32* %d) {
 entry:
@@ -30,7 +30,7 @@ B4:
 !0 = !{!"branch_weights", i32 4, i32 124}
 
 ; CHECK: Machine code for function test1:
-; CHECK: Successors according to CFG: BB#1(67108864) BB#2(2080374784)
+; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}3.12%) BB#2({{[0-9a-fx/= ]+}}96.88%)
 
 @g0 = common global i32 0, align 4