According to my auto-simplifier the most common missed simplifications in

optimized code are:
  (non-negative number)+(power-of-two) != 0 -> true
and
  (x | 1) != 0 -> true
Instcombine knows about the second one of course, but only does it if X|1
has only one use.  These fire thousands of times in the testsuite.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstSimplify/2011-01-18-Compare.ll

@@ -27,6 +27,14 @@ define i1 @zext2(i1 %x) {
 ; CHECK: ret i1 %x
 }
 
+define i1 @zext3() {
+; CHECK: @zext3
+  %e = zext i1 1 to i32
+  %c = icmp ne i32 %e, 0
+  ret i1 %c
+; CHECK: ret i1 true
+}
+
 define i1 @sext(i32 %x) {
 ; CHECK: @sext
   %e1 = sext i32 %x to i64
@@ -43,3 +51,49 @@ define i1 @sext2(i1 %x) {
   ret i1 %c
 ; CHECK: ret i1 %x
 }
+
+define i1 @sext3() {
+; CHECK: @sext3
+  %e = sext i1 1 to i32
+  %c = icmp ne i32 %e, 0
+  ret i1 %c
+; CHECK: ret i1 true
+}
+
+define i1 @add(i32 %x, i32 %y) {
+; CHECK: @add
+  %l = lshr i32 %x, 1
+  %r = lshr i32 %y, 1
+  %s = add i32 %l, %r
+  %c = icmp eq i32 %s, 0
+  ret i1 %c
+; CHECK: ret i1 false
+}
+
+define i1 @add2(i8 %x, i8 %y) {
+; CHECK: @add2
+  %l = or i8 %x, 128
+  %r = or i8 %y, 129
+  %s = add i8 %l, %r
+  %c = icmp eq i8 %s, 0
+  ret i1 %c
+; CHECK: ret i1 false
+}
+
+define i1 @addpowtwo(i32 %x, i32 %y) {
+; CHECK: @addpowtwo
+  %l = lshr i32 %x, 1
+  %r = shl i32 1, %y
+  %s = add i32 %l, %r
+  %c = icmp eq i32 %s, 0
+  ret i1 %c
+; CHECK: ret i1 false
+}
+
+define i1 @or(i32 %x) {
+; CHECK: @or
+  %o = or i32 %x, 1
+  %c = icmp eq i32 %o, 0
+  ret i1 %c
+; CHECK: ret i1 false
+}