implement PR4895, by making FoldOpIntoPhi handle select conditions

that are phi nodes.  Also tighten up FoldOpIntoPhi to treat constantexpr
operands to phis just like other variables, avoiding moving constantexpr
computations around.

Patch by Daniel Dunbar.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82913 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/select.ll b/test/Transforms/InstCombine/select.ll
index 22fe57f237..fc4b82002d 100644
--- a/test/Transforms/InstCombine/select.ll
+++ b/test/Transforms/InstCombine/select.ll
@@ -202,3 +202,25 @@ define i1 @test24(i1 %a, i1 %b) {
         ret i1 %c
 }
 
+define i32 @test25()  {
+entry:
+  br i1 false, label %jump, label %ret
+jump:
+  br label %ret 
+ret:
+  %a = phi i1 [true, %jump], [false, %entry]
+  %b = select i1 %a, i32 10, i32 20
+  ret i32 %b
+}
+
+define i32 @test26()  {
+entry:
+  br i1 false, label %jump, label %ret
+jump:
+  %c = or i1 false, false
+  br label %ret 
+ret:
+  %a = phi i1 [true, %jump], [%c, %entry]
+  %b = select i1 %a, i32 10, i32 20
+  ret i32 %b
+}