Use value ranges to fold ext(trunc) in SCEV when possible.

llvm-svn: 124062

1 files changed, 34 insertions, 0 deletions

diff --git a/llvm/test/Analysis/ScalarEvolution/fold.ll b/llvm/test/Analysis/ScalarEvolution/fold.ll
index 3c1b6ae0fec..90012a38ac5 100644
--- a/llvm/test/Analysis/ScalarEvolution/fold.ll
+++ b/llvm/test/Analysis/ScalarEvolution/fold.ll
@@ -22,3 +22,37 @@ define i8 @test3(i8 %x) {
 ; CHECK: (3 * %x)
   ret i8 %C
 }
+
+define void @test4(i32 %x) {
+entry:
+  %0 = icmp sge i32 %x, 0
+  br i1 %0, label %loop, label %exit
+loop:
+  %A = phi i32 [0, %entry], [%I, %loop]
+  %rand = icmp sgt i32 %A, 10
+  %Z = select i1 %rand, i32 %A, i32 10
+  %B = trunc i32 %Z to i16
+  %C = sext i16 %B to i30
+; CHECK: %C =
+; CHECK-NEXT: (trunc i32 (10 smax {0,+,1}<%loop>) to i30)
+  %D = sext i16 %B to i32
+; CHECK: %D =
+; CHECK-NEXT: (10 smax {0,+,1}<%loop>)
+  %E = sext i16 %B to i34
+; CHECK: %E =
+; CHECK-NEXT: (zext i32 (10 smax {0,+,1}<%loop>) to i34)
+  %F = zext i16 %B to i30
+; CHECK: %F =
+; CHECK-NEXT: (trunc i32 (10 smax {0,+,1}<%loop>) to i30
+  %G = zext i16 %B to i32
+; CHECK: %G =
+; CHECK-NEXT: (10 smax {0,+,1}<%loop>)
+  %H = zext i16 %B to i34
+; CHECK: %H =
+; CHECK-NEXT: (zext i32 (10 smax {0,+,1}<%loop>) to i34)
+  %I = add i32 %A, 1
+  %1 = icmp ne i32 %A, 20
+  br i1 %1, label %loop, label %exit
+exit:
+  ret void
+}
\ No newline at end of file