From 411b9b8153ee95a51a2b7b3ebdb6fec9a7229f5a Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo@fhahn.com>
Date: Wed, 11 May 2022 20:46:48 +0100
Subject: [PATCH] [GVN] Add test case for memdep invalidation bug.

Test case for #30999.
---
 .../Transforms/GVN/condprop-memdep-invalidation.ll | 109 +++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 llvm/test/Transforms/GVN/condprop-memdep-invalidation.ll

diff --git a/llvm/test/Transforms/GVN/condprop-memdep-invalidation.ll b/llvm/test/Transforms/GVN/condprop-memdep-invalidation.ll
new file mode 100644
index 0000000..9ff0aef
--- /dev/null
+++ b/llvm/test/Transforms/GVN/condprop-memdep-invalidation.ll
@@ -0,0 +1,109 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=gvn -S %s | FileCheck %s
+
+; Test case for PR31651.
+
+target datalayout = "p:16:16"
+
+declare void @use(i16) readonly
+
+define i16 @test_PR31651(ptr %ub.16) {
+; CHECK-LABEL: @test_PR31651(
+; CHECK-NEXT:    br label [[LOOP_1_HEADER:%.*]]
+; CHECK:       loop.1.header:
+; CHECK-NEXT:    [[IV_1:%.*]] = phi i16 [ 0, [[TMP0:%.*]] ], [ [[IV_1_NEXT:%.*]], [[LOOP_1_LATCH:%.*]] ]
+; CHECK-NEXT:    [[CMP_1:%.*]] = icmp eq i16 [[IV_1]], 0
+; CHECK-NEXT:    br i1 [[CMP_1]], label [[CONT_1:%.*]], label [[THEN_1:%.*]]
+; CHECK:       then.1:
+; CHECK-NEXT:    [[_TMP18:%.*]] = add i16 [[IV_1]], -1
+; CHECK-NEXT:    [[GEP_1:%.*]] = getelementptr [4 x i16], ptr [[UB_16:%.*]], i16 1, i16 [[_TMP18]]
+; CHECK-NEXT:    [[L_1:%.*]] = load i16, ptr [[GEP_1]], align 2
+; CHECK-NEXT:    br label [[CONT_1]]
+; CHECK:       cont.1:
+; CHECK-NEXT:    [[IV_1_SINK:%.*]] = phi i16 [ [[IV_1]], [[THEN_1]] ], [ 0, [[LOOP_1_HEADER]] ]
+; CHECK-NEXT:    [[SINK:%.*]] = phi i16 [ [[L_1]], [[THEN_1]] ], [ 10, [[LOOP_1_HEADER]] ]
+; CHECK-NEXT:    [[GEP_2:%.*]] = getelementptr [4 x i16], ptr [[UB_16]], i16 1, i16 [[IV_1_SINK]]
+; CHECK-NEXT:    br i1 [[CMP_1]], label [[THEN_2:%.*]], label [[ELSE_2:%.*]]
+; CHECK:       then.2:
+; CHECK-NEXT:    [[GEP_3:%.*]] = getelementptr [4 x i16], ptr [[UB_16]], i16 1, i16 0
+; CHECK-NEXT:    [[L_2:%.*]] = load i16, ptr [[GEP_3]], align 2
+; CHECK-NEXT:    call void @use(i16 [[L_2]])
+; CHECK-NEXT:    br label [[LOOP_1_LATCH]]
+; CHECK:       else.2:
+; CHECK-NEXT:    [[GEP_4:%.*]] = getelementptr [4 x i16], ptr [[UB_16]], i16 1, i16 [[IV_1]]
+; CHECK-NEXT:    [[L_3:%.*]] = load i16, ptr [[GEP_4]], align 2
+; CHECK-NEXT:    call void @use(i16 [[L_3]])
+; CHECK-NEXT:    br label [[LOOP_1_LATCH]]
+; CHECK:       loop.1.latch:
+; CHECK-NEXT:    [[L_42:%.*]] = phi i16 [ [[L_3]], [[ELSE_2]] ], [ [[L_2]], [[THEN_2]] ]
+; CHECK-NEXT:    [[IV_1_NEXT]] = add i16 [[IV_1]], 1
+; CHECK-NEXT:    [[CMP_3:%.*]] = icmp slt i16 [[IV_1_NEXT]], 2
+; CHECK-NEXT:    br i1 [[CMP_3]], label [[LOOP_1_HEADER]], label [[LOOP_2:%.*]]
+; CHECK:       loop.2:
+; CHECK-NEXT:    [[L_4:%.*]] = phi i16 [ [[L_42]], [[LOOP_1_LATCH]] ], [ [[L_4_PRE:%.*]], [[LOOP_2_LOOP_2_CRIT_EDGE:%.*]] ]
+; CHECK-NEXT:    [[IV_2:%.*]] = phi i16 [ 0, [[LOOP_1_LATCH]] ], [ [[IV_2_NEXT:%.*]], [[LOOP_2_LOOP_2_CRIT_EDGE]] ]
+; CHECK-NEXT:    [[SUM:%.*]] = phi i16 [ 0, [[LOOP_1_LATCH]] ], [ [[SUM_NEXT:%.*]], [[LOOP_2_LOOP_2_CRIT_EDGE]] ]
+; CHECK-NEXT:    [[GEP_5:%.*]] = getelementptr [4 x i16], ptr [[UB_16]], i16 1, i16 [[IV_2]]
+; CHECK-NEXT:    [[SUM_NEXT]] = add i16 [[SUM]], [[L_4]]
+; CHECK-NEXT:    [[IV_2_NEXT]] = add i16 [[IV_2]], 1
+; CHECK-NEXT:    [[CMP_4:%.*]] = icmp slt i16 [[IV_2_NEXT]], 2
+; CHECK-NEXT:    br i1 [[CMP_4]], label [[LOOP_2_LOOP_2_CRIT_EDGE]], label [[EXIT:%.*]]
+; CHECK:       loop.2.loop.2_crit_edge:
+; CHECK-NEXT:    [[GEP_5_PHI_TRANS_INSERT:%.*]] = getelementptr [4 x i16], ptr [[UB_16]], i16 1, i16 [[IV_2_NEXT]]
+; CHECK-NEXT:    [[L_4_PRE]] = load i16, ptr [[GEP_5_PHI_TRANS_INSERT]], align 2
+; CHECK-NEXT:    br label [[LOOP_2]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i16 [[SUM_NEXT]]
+;
+  br label %loop.1.header
+
+loop.1.header:
+  %iv.1 = phi i16 [ 0, %0 ], [ %iv.1.next, %loop.1.latch ]
+  %cmp.1 = icmp eq i16 %iv.1, 0
+  br i1 %cmp.1 , label %cont.1, label %then.1
+
+then.1:
+  %_tmp18 = add i16 %iv.1, -1
+  %gep.1 = getelementptr [4 x i16], ptr %ub.16, i16 1, i16 %_tmp18
+  %l.1 = load i16, i16* %gep.1, align 2
+  br label %cont.1
+
+cont.1:
+  %iv.1.sink = phi i16 [ %iv.1, %then.1 ], [ 0, %loop.1.header ]
+  %sink = phi i16 [ %l.1, %then.1 ], [ 10, %loop.1.header ]
+  %gep.2 = getelementptr [4 x i16], ptr %ub.16, i16 1, i16 %iv.1.sink
+  %cmp.2 = icmp eq i16 %iv.1, 0
+  br i1 %cmp.2, label %then.2, label %else.2
+
+then.2:
+  %gep.3 = getelementptr [4 x i16], ptr %ub.16, i16 1, i16 %iv.1
+  %l.2 = load i16, ptr %gep.3, align 2
+  call void @use(i16 %l.2)
+  br label %loop.1.latch
+
+else.2:
+  %gep.4 = getelementptr [4 x i16], ptr %ub.16, i16 1, i16 %iv.1
+  %l.3 = load i16, ptr %gep.4, align 2
+  call void @use(i16 %l.3)
+  br label %loop.1.latch
+
+loop.1.latch:
+  %iv.1.next = add i16 %iv.1, 1
+  %cmp.3 = icmp slt i16 %iv.1.next, 2
+  br i1 %cmp.3, label %loop.1.header, label %loop.2
+
+loop.2:
+  %iv.2 = phi i16 [ 0, %loop.1.latch ], [ %iv.2.next, %loop.2 ]
+  %sum = phi i16 [ 0, %loop.1.latch ], [ %sum.next, %loop.2 ]
+  %gep.5 = getelementptr [4 x i16], ptr %ub.16, i16 1, i16 %iv.2
+  %l.4 = load i16, ptr %gep.5, align 2
+  %sum.next = add i16 %sum, %l.4
+  %iv.2.next = add i16 %iv.2, 1
+  %cmp.4 = icmp slt i16 %iv.2.next, 2
+  br i1 %cmp.4, label %loop.2, label %exit
+
+exit:
+  ret i16 %sum.next
+
+  uselistorder ptr %ub.16, { 4, 3, 2, 0, 1 }
+}
-- 
2.7.4