From b1c0cc22dd5854a77e5699e80ce37545315b98ed Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 25 Jun 2013 21:57:38 +0000
Subject: [PATCH] Print block frequencies in decimal form.

This is easier to read than the internal fixed-point representation.

If anybody knows the correct algorithm for converting fixed-point
numbers to base 10, feel free to fix it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184881 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Support/BlockFrequency.cpp            | 11 +++++++-
 test/Analysis/BlockFrequencyInfo/basic.ll | 32 +++++++++++------------
 2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp
index 84a993e3e5b..572dbf57654 100644
--- a/lib/Support/BlockFrequency.cpp
+++ b/lib/Support/BlockFrequency.cpp
@@ -117,7 +117,16 @@ BlockFrequency::operator+(const BlockFrequency &Prob) const {
 }
 
 void BlockFrequency::print(raw_ostream &OS) const {
-  OS << Frequency;
+  // Convert fixed-point number to decimal.
+  OS << Frequency / getEntryFrequency() << ".";
+  uint64_t Rem = Frequency % getEntryFrequency();
+  uint64_t Eps = 1;
+  do {
+    Rem *= 10;
+    Eps *= 10;
+    OS << Rem / getEntryFrequency();
+    Rem = Rem % getEntryFrequency();
+  } while (Rem >= Eps/2);
 }
 
 namespace llvm {
diff --git a/test/Analysis/BlockFrequencyInfo/basic.ll b/test/Analysis/BlockFrequencyInfo/basic.ll
index a9be431b709..43dd264402d 100644
--- a/test/Analysis/BlockFrequencyInfo/basic.ll
+++ b/test/Analysis/BlockFrequencyInfo/basic.ll
@@ -2,12 +2,12 @@
 
 define i32 @test1(i32 %i, i32* %a) {
 ; CHECK: Printing analysis {{.*}} for function 'test1'
-; CHECK: entry = 16384
+; CHECK: entry = 1.0
 entry:
   br label %body
 
 ; Loop backedges are weighted and thus their bodies have a greater frequency.
-; CHECK: body = 524288
+; CHECK: body = 32.0
 body:
   %iv = phi i32 [ 0, %entry ], [ %next, %body ]
   %base = phi i32 [ 0, %entry ], [ %sum, %body ]
@@ -18,29 +18,29 @@ body:
   %exitcond = icmp eq i32 %next, %i
   br i1 %exitcond, label %exit, label %body
 
-; CHECK: exit = 16384
+; CHECK: exit = 1.0
 exit:
   ret i32 %sum
 }
 
 define i32 @test2(i32 %i, i32 %a, i32 %b) {
 ; CHECK: Printing analysis {{.*}} for function 'test2'
-; CHECK: entry = 16384
+; CHECK: entry = 1.0
 entry:
   %cond = icmp ult i32 %i, 42
   br i1 %cond, label %then, label %else, !prof !0
 
 ; The 'then' branch is predicted more likely via branch weight metadata.
-; CHECK: then = 15420
+; CHECK: then = 0.94116
 then:
   br label %exit
 
-; CHECK: else = 963
+; CHECK: else = 0.05877
 else:
   br label %exit
 
-; FIXME: It may be a bug that we don't sum back to 16384.
-; CHECK: exit = 16383
+; FIXME: It may be a bug that we don't sum back to 1.0.
+; CHECK: exit = 0.99993
 exit:
   %result = phi i32 [ %a, %then ], [ %b, %else ]
   ret i32 %result
@@ -50,36 +50,36 @@ exit:
 
 define i32 @test3(i32 %i, i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) {
 ; CHECK: Printing analysis {{.*}} for function 'test3'
-; CHECK: entry = 16384
+; CHECK: entry = 1.0
 entry:
   switch i32 %i, label %case_a [ i32 1, label %case_b
                                  i32 2, label %case_c
                                  i32 3, label %case_d
                                  i32 4, label %case_e ], !prof !1
 
-; CHECK: case_a = 819
+; CHECK: case_a = 0.04998
 case_a:
   br label %exit
 
-; CHECK: case_b = 819
+; CHECK: case_b = 0.04998
 case_b:
   br label %exit
 
 ; The 'case_c' branch is predicted more likely via branch weight metadata.
-; CHECK: case_c = 13107
+; CHECK: case_c = 0.79998
 case_c:
   br label %exit
 
-; CHECK: case_d = 819
+; CHECK: case_d = 0.04998
 case_d:
   br label %exit
 
-; CHECK: case_e = 819
+; CHECK: case_e = 0.04998
 case_e:
   br label %exit
 
-; FIXME: It may be a bug that we don't sum back to 16384.
-; CHECK: exit = 16383
+; FIXME: It may be a bug that we don't sum back to 1.0.
+; CHECK: exit = 0.99993
 exit:
   %result = phi i32 [ %a, %case_a ],
                     [ %b, %case_b ],
-- 
2.34.1