[Profile] Fix builtin_expect lowering bug

The lowerer wrongly assumes the ICMP instruction 
 1) always has a constant operand;
 2) the operand has value 0.

It also assumes the expected value can only be one, thus
other values other than one will be considered 'zero'.

This leads to wrong profile annotation when other integer values
are used other than 0, 1 in the comparison or in the expect intrinsic.

Also missing is handling of equal predicate.

This patch fixes all the above problems.

Differential Revision: http://reviews.llvm.org/D33757

llvm-svn: 304453

1 files changed, 104 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LowerExpectIntrinsic/expect_nonboolean.ll b/llvm/test/Transforms/LowerExpectIntrinsic/expect_nonboolean.ll
new file mode 100644
index 00000000000..736ddc32856
--- /dev/null
+++ b/llvm/test/Transforms/LowerExpectIntrinsic/expect_nonboolean.ll
@@ -0,0 +1,104 @@
+; RUN: opt -lower-expect  -S -o - < %s | FileCheck %s
+; RUN: opt -S -passes='function(lower-expect)' < %s | FileCheck %s
+
+define i32 @foo(i32 %arg) #0 {
+; CHECK-LABEL: @foo(i32{{.*}})
+bb:
+  %tmp = sext i32 %arg to i64
+  %tmp1 = call i64 @llvm.expect.i64(i64 %tmp, i64 4)
+  %tmp2 = icmp ne i64 %tmp1, 0
+  br i1 %tmp2, label %bb3, label %bb5
+; CHECK: br i1 %tmp2{{.*}}!prof [[LIKELY:![0-9]+]]
+
+bb3:                                              ; preds = %bb
+  %tmp4 = call i32 (...) @bar()
+  br label %bb5
+
+bb5:                                              ; preds = %bb3, %bb
+  ret i32 1
+}
+
+define i32 @foo2(i32 %arg) #0 {
+; CHECK-LABEL: @foo2
+bb:
+  %tmp = sext i32 %arg to i64
+  %tmp1 = call i64 @llvm.expect.i64(i64 %tmp, i64 4)
+  %tmp2 = icmp eq i64 %tmp1, 2
+  br i1 %tmp2, label %bb3, label %bb5
+; CHECK: br i1 %tmp2{{.*}}!prof [[UNLIKELY:![0-9]+]]
+
+bb3:                                              ; preds = %bb
+  %tmp4 = call i32 (...) @bar()
+  br label %bb5
+
+bb5:                                              ; preds = %bb3, %bb
+  ret i32 1
+}
+
+define i32 @foo3(i32 %arg) #0 {
+; CHECK-LABEL: @foo3
+bb:
+  %tmp = sext i32 %arg to i64
+  %tmp1 = call i64 @llvm.expect.i64(i64 %tmp, i64 4)
+  %tmp2 = icmp eq i64 %tmp1, 4
+  br i1 %tmp2, label %bb3, label %bb5
+; CHECK: br i1 %tmp2{{.*}}!prof [[LIKELY]]
+
+bb3:                                              ; preds = %bb
+  %tmp4 = call i32 (...) @bar()
+  br label %bb5
+
+bb5:                                              ; preds = %bb3, %bb
+  ret i32 1
+}
+
+define i32 @foo4(i32 %arg) #0 {
+; CHECK-LABEL: @foo4
+bb:
+  %tmp = sext i32 %arg to i64
+  %tmp1 = call i64 @llvm.expect.i64(i64 %tmp, i64 4)
+  %tmp2 = icmp ne i64 %tmp1, 2
+  br i1 %tmp2, label %bb3, label %bb5
+; CHECK: br i1 %tmp2{{.*}}!prof [[LIKELY]]
+
+bb3:                                              ; preds = %bb
+  %tmp4 = call i32 (...) @bar()
+  br label %bb5
+
+bb5:                                              ; preds = %bb3, %bb
+  ret i32 1
+}
+
+define i32 @foo5(i32 %arg, i32 %arg1) #0 {
+; CHECK-LABEL: @foo5
+bb:
+  %tmp = sext i32 %arg1 to i64
+  %tmp2 = call i64 @llvm.expect.i64(i64 %tmp, i64 4)
+  %tmp3 = sext i32 %arg to i64
+  %tmp4 = icmp ne i64 %tmp2, %tmp3
+  br i1 %tmp4, label %bb5, label %bb7
+; CHECK-NOT: !prof
+
+bb5:                                              ; preds = %bb
+  %tmp6 = call i32 (...) @bar()
+  br label %bb7
+
+bb7:                                              ; preds = %bb5, %bb
+  ret i32 1
+}
+
+declare i64 @llvm.expect.i64(i64, i64) #1
+
+declare i32 @bar(...) local_unnamed_addr #0
+
+attributes #0 = { nounwind uwtable }
+attributes #1 = { nounwind readnone }
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 5.0.0 (trunk 304373)"}
+; CHECK: [[LIKELY]] = !{!"branch_weights", i32 2000, i32 1}
+; CHECK: [[UNLIKELY]] = !{!"branch_weights", i32 1, i32 2000}
+