[ConstraintElim] Add set of tests where a loop iv is used in exit.

Test cases inspired by
https://github.com/llvm/llvm-project/issues/90417.

1 files changed, 277 insertions, 0 deletions

diff --git a/llvm/test/Transforms/ConstraintElimination/induction-condition-in-loop-exit.ll b/llvm/test/Transforms/ConstraintElimination/induction-condition-in-loop-exit.ll
new file mode 100644
index 0000000..44ce82b5
--- /dev/null
+++ b/llvm/test/Transforms/ConstraintElimination/induction-condition-in-loop-exit.ll
@@ -0,0 +1,277 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -p constraint-elimination -S %s | FileCheck %s
+
+define i1 @multi_exiting_loop_eq_same_unique_exit_const_compare_known(ptr %s) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_eq_same_unique_exit_const_compare_known(
+; CHECK-SAME: ptr [[S:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[T:%.*]] = icmp ult i32 [[IV]], 1235
+; CHECK-NEXT:    ret i1 [[T]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp eq i32 %iv, 1234
+  br i1 %exitcond.not, label %exit, label %loop.latch
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %t = icmp ult i32 %iv, 1235
+  ret i1 %t
+}
+
+define i1 @multi_exiting_loop_eq_same_exit_with_out_loop_preds_const_compare_not_known(ptr %s, i1 %pre.c, i32 %x) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_eq_same_exit_with_out_loop_preds_const_compare_not_known(
+; CHECK-SAME: ptr [[S:%.*]], i1 [[PRE_C:%.*]], i32 [[X:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br i1 [[PRE_C]], label %[[LOOP_HEADER:.*]], label %[[EXIT:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT]], label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[P:%.*]] = phi i32 [ [[X]], %[[ENTRY]] ], [ [[IV]], %[[LOOP_HEADER]] ], [ [[IV]], %[[LOOP_LATCH]] ]
+; CHECK-NEXT:    [[U:%.*]] = icmp ult i32 [[P]], 1235
+; CHECK-NEXT:    ret i1 [[U]]
+;
+entry:
+  br i1 %pre.c, label %loop.header, label %exit
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp eq i32 %iv, 1234
+  br i1 %exitcond.not, label %exit, label %loop.latch
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %p = phi i32 [ %x, %entry ], [ %iv, %loop.header ], [ %iv, %loop.latch ]
+  %u = icmp ult i32 %p, 1235
+  ret i1 %u
+}
+
+define i1 @multi_exiting_loop_eq_same_unique_exit_successors_swapped(ptr %s) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_eq_same_unique_exit_successors_swapped(
+; CHECK-SAME: ptr [[S:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[LOOP_LATCH]], label %[[EXIT:.*]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[U:%.*]] = icmp ult i32 [[IV]], 1235
+; CHECK-NEXT:    ret i1 [[U]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp eq i32 %iv, 1234
+  br i1 %exitcond.not, label %loop.latch, label %exit
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %u = icmp ult i32 %iv, 1235
+  ret i1 %u
+}
+
+define i1 @multi_exiting_loop_eq_same_unique_exit_const_compare_not_known(ptr %s) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_eq_same_unique_exit_const_compare_not_known(
+; CHECK-SAME: ptr [[S:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[U:%.*]] = icmp ult i32 [[IV]], 1234
+; CHECK-NEXT:    ret i1 [[U]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp eq i32 %iv, 1234
+  br i1 %exitcond.not, label %exit, label %loop.latch
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %u = icmp ult i32 %iv, 1234
+  ret i1 %u
+}
+
+define i1 @multi_exiting_loop_eq_same_unique_exit_var_compare_known(ptr %s, i32 %N) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_eq_same_unique_exit_var_compare_known(
+; CHECK-SAME: ptr [[S:%.*]], i32 [[N:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[T:%.*]] = icmp ule i32 [[IV]], [[N]]
+; CHECK-NEXT:    ret i1 [[T]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp eq i32 %iv, %N
+  br i1 %exitcond.not, label %exit, label %loop.latch
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %t = icmp ule i32 %iv, %N
+  ret i1 %t
+}
+
+define i1 @multi_exiting_loop_ne_same_unique_exit_const_compare_known(ptr %s) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_ne_same_unique_exit_const_compare_known(
+; CHECK-SAME: ptr [[S:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp ne i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[LOOP_LATCH]], label %[[EXIT:.*]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[T:%.*]] = icmp ult i32 [[IV]], 1235
+; CHECK-NEXT:    ret i1 [[T]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp ne i32 %iv, 1234
+  br i1 %exitcond.not, label %loop.latch, label %exit
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %t = icmp ult i32 %iv, 1235
+  ret i1 %t
+}
+
+define i1 @multi_exiting_loop_ne_same_unique_exit_successors_swapped(ptr %s) {
+; CHECK-LABEL: define i1 @multi_exiting_loop_ne_same_unique_exit_successors_swapped(
+; CHECK-SAME: ptr [[S:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_HEADER:.*]]
+; CHECK:       [[LOOP_HEADER]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP_LATCH:.*]] ]
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp ne i32 [[IV]], 1234
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP_LATCH]]
+; CHECK:       [[LOOP_LATCH]]:
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[S]], i32 [[IV]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
+; CHECK-NEXT:    [[LATCH_C:%.*]] = icmp ult i8 [[TMP0]], 10
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    br i1 [[LATCH_C]], label %[[LOOP_HEADER]], label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[U:%.*]] = icmp ult i32 [[IV]], 1235
+; CHECK-NEXT:    ret i1 [[U]]
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop.latch ]
+  %exitcond.not = icmp ne i32 %iv, 1234
+  br i1 %exitcond.not, label %exit, label %loop.latch
+
+loop.latch:
+  %arrayidx = getelementptr inbounds i8, ptr %s, i32 %iv
+  %0 = load i8, ptr %arrayidx, align 1
+  %latch.c = icmp ult i8 %0, 10
+  %iv.next = add nuw nsw i32 %iv, 1
+  br i1 %latch.c, label %loop.header, label %exit
+
+exit:
+  %u = icmp ult i32 %iv, 1235
+  ret i1 %u
+}