[llvm] 02ab87f - [SimplifyCFG] Add additional jump threading test (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2022-07-05T13:57:58+02:00
New Revision: 02ab87f54305a4f8b741596538c70d7953440971

URL: https://github.com/llvm/llvm-project/commit/02ab87f54305a4f8b741596538c70d7953440971
DIFF: https://github.com/llvm/llvm-project/commit/02ab87f54305a4f8b741596538c70d7953440971.diff

LOG: [SimplifyCFG] Add additional jump threading test (NFC)

A case where multiple predecessors can be threaded over the same
edge, with a phi node in the threaded block.

Added: 
    

Modified: 
    llvm/test/Transforms/SimplifyCFG/jump-threading.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/SimplifyCFG/jump-threading.ll b/llvm/test/Transforms/SimplifyCFG/jump-threading.ll
index 59195660a392..a9191b3c61d9 100644
--- a/llvm/test/Transforms/SimplifyCFG/jump-threading.ll
+++ b/llvm/test/Transforms/SimplifyCFG/jump-threading.ll
@@ -4,6 +4,7 @@
 declare void @foo()
 declare void @bar()
 declare void @use.i1(i1)
+declare void @use.i32(i32)
 
 define void @test_phi_simple(i1 %c) {
 ; CHECK-LABEL: @test_phi_simple(
@@ -262,3 +263,47 @@ else2:
 join2:
   ret void
 }
+
+define void @test_multiple_threadable_preds_with_phi(i1 %cond1, i1 %cond2) {
+; CHECK-LABEL: @test_multiple_threadable_preds_with_phi(
+; CHECK-NEXT:    br i1 [[COND1:%.*]], label [[IF1:%.*]], label [[IF2:%.*]]
+; CHECK:       if1:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br i1 [[COND2:%.*]], label [[IF3_CRITEDGE1:%.*]], label [[EXIT:%.*]]
+; CHECK:       if2:
+; CHECK-NEXT:    call void @bar()
+; CHECK-NEXT:    br i1 [[COND2]], label [[IF3_CRITEDGE:%.*]], label [[EXIT]]
+; CHECK:       if3.critedge:
+; CHECK-NEXT:    call void @use.i32(i32 2)
+; CHECK-NEXT:    br label [[IF3:%.*]]
+; CHECK:       if3.critedge1:
+; CHECK-NEXT:    call void @use.i32(i32 1)
+; CHECK-NEXT:    br label [[IF3]]
+; CHECK:       if3:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+  br i1 %cond1, label %if1, label %if2
+
+if1:
+  call void @foo()
+  br i1 %cond2, label %join, label %exit
+
+if2:
+  call void @bar()
+  br i1 %cond2, label %join, label %exit
+
+join:
+  %phi = phi i32 [ 1, %if1 ], [ 2, %if2 ]
+  call void @use.i32(i32 %phi)
+  br i1 %cond2, label %if3, label %exit
+
+if3:
+  call void @foo()
+  br label %exit
+
+exit:
+  ret void
+}