[llvm] f893d35 - [IndVars] Add test for PR60944 (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-03-07T15:33:35+01:00
New Revision: f893d35c0d461aa1e1d89b9633868b0913f15dcc

URL: https://github.com/llvm/llvm-project/commit/f893d35c0d461aa1e1d89b9633868b0913f15dcc
DIFF: https://github.com/llvm/llvm-project/commit/f893d35c0d461aa1e1d89b9633868b0913f15dcc.diff

LOG: [IndVars] Add test for PR60944 (NFC)

Added: 
    llvm/test/Transforms/IndVarSimplify/pr60944.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/IndVarSimplify/pr60944.ll b/llvm/test/Transforms/IndVarSimplify/pr60944.ll
new file mode 100644
index 0000000000000..beac42d2fb062
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/pr60944.ll
@@ -0,0 +1,55 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S -passes=indvars < %s | FileCheck %s
+
+ at x = global i32 0
+
+; FIXME: This is a miscompile.
+; %loop2 is never entered and we cannot derive any fact about %iv from it.
+define i32 @main(i32 %iv.start, i32 %arg2) mustprogress {
+; CHECK-LABEL: define i32 @main
+; CHECK-SAME: (i32 [[IV_START:%.*]], i32 [[ARG2:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[LOOP_LATCH:%.*]] ], [ [[IV_START]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    br i1 false, label [[LOOP2_PREHEADER:%.*]], label [[LOOP_LATCH]]
+; CHECK:       loop2.preheader:
+; CHECK-NEXT:    br label [[LOOP2:%.*]]
+; CHECK:       loop2:
+; CHECK-NEXT:    br i1 true, label [[LOOP2_EXIT:%.*]], label [[LOOP2]]
+; CHECK:       loop2.exit:
+; CHECK-NEXT:    br label [[LOOP_LATCH]]
+; CHECK:       loop.latch:
+; CHECK-NEXT:    [[IV_NEXT]] = sdiv i32 [[ARG2]], [[IV]]
+; CHECK-NEXT:    br i1 false, label [[LOOP_EXIT:%.*]], label [[LOOP]]
+; CHECK:       loop.exit:
+; CHECK-NEXT:    [[IV_NEXT_LCSSA:%.*]] = phi i32 [ [[IV_NEXT]], [[LOOP_LATCH]] ]
+; CHECK-NEXT:    ret i32 [[IV_NEXT_LCSSA]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ %iv.next, %loop.latch ], [ %iv.start, %entry ]
+  br i1 false, label %loop2.preheader, label %loop.latch
+
+loop2.preheader:
+  br label %loop2
+
+loop2:
+  %x = load i32, ptr @x, align 4
+  %cmp1 = icmp ult i32 %iv, %x
+  br i1 %cmp1, label %loop2.exit, label %loop2
+
+loop2.exit:
+  br label %loop.latch
+
+loop.latch:
+  %iv.next = sdiv i32 %arg2, %iv
+  %cmp2 = icmp eq i32 %iv, -1
+  br i1 %cmp2, label %loop.exit, label %loop
+
+loop.exit:
+  %iv.next.lcssa = phi i32 [ %iv.next, %loop.latch ]
+  ret i32 %iv.next.lcssa
+}