diff options
| author | Rong Xu <xur@google.com> | 2017-11-14 21:44:09 +0000 |
|---|---|---|
| committer | Rong Xu <xur@google.com> | 2017-11-14 21:44:09 +0000 |
| commit | 68761036ca36383712767b9ee969fae2df7f58b8 (patch) | |
| tree | f6d3d31b4a8f41efb55a66e7e59ef0da0e199cfb /test/CodeGen/Generic | |
| parent | bd3b99d54291d7c2be31804ce8ffc8c1e9aab062 (diff) | |
[CodeGen] Peel off the dominant case in switch statement in lowering
This patch peels off the top case in switch statement into a branch if the
probability exceeds a threshold. This will help the branch prediction and
avoids the extra compares when lowering into chain of branches.
Differential Revision: http://reviews.llvm.org/D39262
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318202 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/Generic')
| -rw-r--r-- | test/CodeGen/Generic/MachineBranchProb.ll | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/test/CodeGen/Generic/MachineBranchProb.ll b/test/CodeGen/Generic/MachineBranchProb.ll index 8207fa8ce0f..75e9a191e3d 100644 --- a/test/CodeGen/Generic/MachineBranchProb.ll +++ b/test/CodeGen/Generic/MachineBranchProb.ll @@ -19,12 +19,15 @@ entry: i64 1, label %sw.bb i64 4, label %sw.bb i64 5, label %sw.bb1 + i64 15, label %sw.bb ], !prof !0 ; CHECK: BB#0: derived from LLVM BB %entry -; CHECK: Successors according to CFG: BB#2({{[0-9a-fx/= ]+}}75.29%) BB#4({{[0-9a-fx/= ]+}}24.71%) +; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}92.17%) BB#4({{[0-9a-fx/= ]+}}7.83%) ; CHECK: BB#4: derived from LLVM BB %entry -; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}47.62%) BB#5({{[0-9a-fx/= ]+}}52.38%) +; CHECK: Successors according to CFG: BB#2({{[0-9a-fx/= ]+}}75.29%) BB#5({{[0-9a-fx/= ]+}}24.71%) ; CHECK: BB#5: derived from LLVM BB %entry +; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}47.62%) BB#6({{[0-9a-fx/= ]+}}52.38%) +; CHECK: BB#6: derived from LLVM BB %entry ; CHECK: Successors according to CFG: BB#1({{[0-9a-fx/= ]+}}36.36%) BB#3({{[0-9a-fx/= ]+}}63.64%) sw.bb: @@ -40,7 +43,7 @@ return: ret i32 %retval.0 } -!0 = !{!"branch_weights", i32 7, i32 6, i32 4, i32 4, i32 64} +!0 = !{!"branch_weights", i32 7, i32 6, i32 4, i32 4, i32 64, i21 1000} declare void @g(i32) |