[llvm] [InstCombine] Fold `ceil(X / (2 ^ C)) == 0` -> `X == 0` (PR #143683)

[Yingwei Zheng via llvm-commits]

================
@@ -0,0 +1,176 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i1 @ceil_shift4(i32 %arg0) {
+; CHECK-LABEL: define i1 @ceil_shift4(
+; CHECK-SAME: i32 [[ARG0:%.*]]) {
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[ARG0]], 0
+; CHECK-NEXT:    ret i1 [[TMP1]]
+;
+  %1 = lshr i32 %arg0, 4
----------------
dtcxzyw wrote:

Use named values.

https://github.com/llvm/llvm-project/pull/143683