[IndVars] Add tests for llvm#79861 (NFC)

Author: nikic

Diff for: llvm/test/Transforms/IndVarSimplify/pr79861.ll

@@ -0,0 +1,104 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -S -passes=indvars < %s | FileCheck %s
+
+target datalayout = "n64"
+
+declare void @use(i64)
+
+define void @or_disjoint() {
+; CHECK-LABEL: define void @or_disjoint() {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 2, [[ENTRY:%.*]] ], [ [[IV_DEC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[OR:%.*]] = or disjoint i64 [[IV]], 1
+; CHECK-NEXT:    call void @use(i64 [[OR]])
+; CHECK-NEXT:    [[IV_DEC]] = add nsw i64 [[IV]], -1
+; CHECK-NEXT:    [[EXIT_COND:%.*]] = icmp eq i64 [[IV_DEC]], 0
+; CHECK-NEXT:    br i1 [[EXIT_COND]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 2, %entry ], [ %iv.dec, %loop ]
+  %or = or disjoint i64 %iv, 1
+  %add = add nsw i64 %iv, 1
+  %sel = select i1 false, i64 %or, i64 %add
+  call void @use(i64 %sel)
+
+  %iv.dec = add nsw i64 %iv, -1
+  %exit.cond = icmp eq i64 %iv.dec, 0
+  br i1 %exit.cond, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+define void @add_nowrap_flags(i64 %n) {
+; CHECK-LABEL: define void @add_nowrap_flags(
+; CHECK-SAME: i64 [[N:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[ADD1:%.*]] = add nuw nsw i64 [[IV]], 123
+; CHECK-NEXT:    call void @use(i64 [[ADD1]])
+; CHECK-NEXT:    [[IV_INC]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[EXIT_COND:%.*]] = icmp eq i64 [[IV_INC]], [[N]]
+; CHECK-NEXT:    br i1 [[EXIT_COND]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.inc, %loop ]
+  %add1 = add nuw nsw i64 %iv, 123
+  %add2 = add i64 %iv, 123
+  %sel = select i1 false, i64 %add1, i64 %add2
+  call void @use(i64 %sel)
+
+  %iv.inc = add i64 %iv, 1
+  %exit.cond = icmp eq i64 %iv.inc, %n
+  br i1 %exit.cond, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+
+define void @expander_or_disjoint(i64 %n) {
+; CHECK-LABEL: define void @expander_or_disjoint(
+; CHECK-SAME: i64 [[N:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[OR:%.*]] = or i64 [[N]], 1
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_INC:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[IV_INC]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[ADD:%.*]] = add i64 [[IV]], [[OR]]
+; CHECK-NEXT:    call void @use(i64 [[ADD]])
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[IV_INC]], [[OR]]
+; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %or = or disjoint i64 %n, 1
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.inc, %loop ]
+  %iv.inc = add i64 %iv, 1
+  %add = add i64 %iv, %or
+  call void @use(i64 %add)
+  %cmp = icmp ult i64 %iv, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret void
+}