From 34637bbe27d3971025cba02dfd4e52a46024f3d7 Mon Sep 17 00:00:00 2001
From: Philip Reames <listmail@philipreames.com>
Date: Tue, 9 Mar 2021 11:39:10 -0800
Subject: [PATCH] [tests] precommit test for an upcoming change

---
 llvm/test/CodeGen/X86/usub_inc_iv.ll | 99 ++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/llvm/test/CodeGen/X86/usub_inc_iv.ll b/llvm/test/CodeGen/X86/usub_inc_iv.ll
index a3097e9..da0fde1 100644
--- a/llvm/test/CodeGen/X86/usub_inc_iv.ll
+++ b/llvm/test/CodeGen/X86/usub_inc_iv.ll
@@ -306,3 +306,102 @@ exit:                                             ; preds = %loop
 failure:                                          ; preds = %backedge
   unreachable
 }
+
+
+; test_01, but with an additional use of %iv.next outside the loop
+define i32 @test_06(i32* %p, i64 %len, i32 %x) {
+; CHECK-LABEL: @test_06(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp eq i64 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND_1]], label [[EXIT:%.*]], label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[SUNKADDR:%.*]] = mul i64 [[IV]], 4
+; CHECK-NEXT:    [[TMP0:%.*]] = bitcast i32* [[P:%.*]] to i8*
+; CHECK-NEXT:    [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP0]], i64 [[SUNKADDR]]
+; CHECK-NEXT:    [[SUNKADDR2:%.*]] = getelementptr i8, i8* [[SUNKADDR1]], i64 -4
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast i8* [[SUNKADDR2]] to i32*
+; CHECK-NEXT:    [[LOADED:%.*]] = load atomic i32, i32* [[TMP1]] unordered, align 4
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], -1
+; CHECK-NEXT:    [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
+; CHECK-NEXT:    br i1 [[COND_2]], label [[FAILURE:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i32 -1
+; CHECK:       failure:
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i64 [[IV_NEXT]] to i32
+; CHECK-NEXT:    ret i32 [[TRUNC]]
+;
+entry:
+  %scevgep = getelementptr i32, i32* %p, i64 -1
+  br label %loop
+
+loop:                                             ; preds = %backedge, %entry
+  %iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
+  %cond_1 = icmp eq i64 %iv, 0
+  br i1 %cond_1, label %exit, label %backedge
+
+backedge:                                         ; preds = %loop
+  %scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
+  %loaded = load atomic i32, i32* %scevgep1 unordered, align 4
+  %iv.next = add i64 %iv, -1
+  %cond_2 = icmp eq i32 %loaded, %x
+  br i1 %cond_2, label %failure, label %loop
+
+exit:
+  ret i32 -1
+
+failure:
+  %trunc = trunc i64 %iv.next to i32
+  ret i32 %trunc
+}
+
+
+; Extra use outside loop which prevents us moving the increment to the cmp
+define i32 @test_07_neg(i32* %p, i64 %len, i32 %x) {
+; CHECK-LABEL: @test_07_neg(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[LEN:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], -1
+; CHECK-NEXT:    [[SUNKADDR:%.*]] = mul i64 [[IV_NEXT]], 4
+; CHECK-NEXT:    [[TMP0:%.*]] = bitcast i32* [[P:%.*]] to i8*
+; CHECK-NEXT:    [[SUNKADDR1:%.*]] = getelementptr i8, i8* [[TMP0]], i64 [[SUNKADDR]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast i8* [[SUNKADDR1]] to i32*
+; CHECK-NEXT:    [[LOADED:%.*]] = load atomic i32, i32* [[TMP1]] unordered, align 4
+; CHECK-NEXT:    [[COND_2:%.*]] = icmp eq i32 [[LOADED]], [[X:%.*]]
+; CHECK-NEXT:    br i1 [[COND_2]], label [[FAILURE:%.*]], label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[COND_1:%.*]] = icmp eq i64 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND_1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i32 -1
+; CHECK:       failure:
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i64 [[IV_NEXT]] to i32
+; CHECK-NEXT:    ret i32 [[TRUNC]]
+;
+entry:
+  %scevgep = getelementptr i32, i32* %p, i64 -1
+  br label %loop
+
+loop:
+  %iv = phi i64 [ %iv.next, %backedge ], [ %len, %entry ]
+  %iv.next = add i64 %iv, -1
+  %scevgep1 = getelementptr i32, i32* %scevgep, i64 %iv
+  %loaded = load atomic i32, i32* %scevgep1 unordered, align 4
+  %cond_2 = icmp eq i32 %loaded, %x
+  br i1 %cond_2, label %failure, label %backedge
+
+backedge:
+  %cond_1 = icmp eq i64 %iv, 0
+  br i1 %cond_1, label %exit, label %loop
+
+exit:
+  ret i32 -1
+
+failure:
+  %trunc = trunc i64 %iv.next to i32
+  ret i32 %trunc
+}
-- 
2.7.4