[llvm] e4da0f9 - [Test] Add test showing missing opportunity in range inference for SCEV
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 16 01:41:23 PDT 2021
Author: Max Kazantsev
Date: 2021-09-16T15:40:56+07:00
New Revision: e4da0f9657b475f62b68a7e7e6cc06855e2f4985
URL: https://github.com/llvm/llvm-project/commit/e4da0f9657b475f62b68a7e7e6cc06855e2f4985
DIFF: https://github.com/llvm/llvm-project/commit/e4da0f9657b475f62b68a7e7e6cc06855e2f4985.diff
LOG: [Test] Add test showing missing opportunity in range inference for SCEV
Added:
llvm/test/Analysis/ScalarEvolution/outer_phi.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Analysis/ScalarEvolution/outer_phi.ll b/llvm/test/Analysis/ScalarEvolution/outer_phi.ll
new file mode 100644
index 0000000000000..09a075e38f511
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/outer_phi.ll
@@ -0,0 +1,119 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt < %s -S -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s
+
+declare i1 @cond()
+
+define i32 @test_01(i32 %a, i32 %b) {
+; CHECK-LABEL: 'test_01'
+; CHECK-NEXT: Classifying expressions for: @test_01
+; CHECK-NEXT: %outer.iv = phi i32 [ 0, %entry ], [ %iv.next, %outer.backedge ]
+; CHECK-NEXT: --> %outer.iv U: [0,-2147483647) S: [0,-2147483647) Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
+; CHECK-NEXT: %iv = phi i32 [ 0, %outer ], [ %iv.next, %inner.backedge ]
+; CHECK-NEXT: --> {0,+,1}<nuw><nsw><%inner> U: [0,-2147483648) S: [0,-2147483648) Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
+; CHECK-NEXT: %iv.next = add nuw nsw i32 %iv, 1
+; CHECK-NEXT: --> {1,+,1}<nuw><%inner> U: [1,-2147483647) S: [1,-2147483647) Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
+; CHECK-NEXT: %inner.loop.cond = call i1 @cond()
+; CHECK-NEXT: --> %inner.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Variant, %outer: Variant }
+; CHECK-NEXT: %outer.loop.cond = call i1 @cond()
+; CHECK-NEXT: --> %outer.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
+; CHECK-NEXT: Determining loop execution counts for: @test_01
+; CHECK-NEXT: Loop %inner: <multiple exits> Unpredictable backedge-taken count.
+; CHECK-NEXT: exit count for inner: %b
+; CHECK-NEXT: exit count for inner.backedge: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: Loop %inner: max backedge-taken count is 2147483647
+; CHECK-NEXT: Loop %inner: Unpredictable predicated backedge-taken count.
+; CHECK-NEXT: Loop %outer: <multiple exits> Unpredictable backedge-taken count.
+; CHECK-NEXT: exit count for inner: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: exit count for outer.backedge: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: Loop %outer: Unpredictable max backedge-taken count.
+; CHECK-NEXT: Loop %outer: Unpredictable predicated backedge-taken count.
+;
+entry:
+ %b_is_non_negative = icmp sge i32 %b, 0
+ br i1 %b_is_non_negative, label %outer, label %failure
+
+outer:
+ %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
+ br label %inner
+
+inner:
+ %iv = phi i32 [0, %outer], [%iv.next, %inner.backedge]
+ %signed_cond = icmp slt i32 %iv, %b
+ br i1 %signed_cond, label %inner.backedge, label %side.exit
+
+inner.backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %inner.loop.cond = call i1 @cond()
+ br i1 %inner.loop.cond, label %inner, label %outer.backedge
+
+outer.backedge:
+ %outer.loop.cond = call i1 @cond()
+ br i1 %outer.loop.cond, label %outer, label %exit
+
+failure:
+ unreachable
+
+side.exit:
+ ret i32 0
+
+exit:
+ ret i32 1
+}
+
+; FIXME: both outer.iv and iv here can be proved non-negative.
+define i32 @test_02(i32 %a, i32 %b) {
+; CHECK-LABEL: 'test_02'
+; CHECK-NEXT: Classifying expressions for: @test_02
+; CHECK-NEXT: %outer.iv = phi i32 [ 0, %entry ], [ %iv.next, %outer.backedge ]
+; CHECK-NEXT: --> %outer.iv U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
+; CHECK-NEXT: %iv = phi i32 [ %outer.iv, %outer ], [ %iv.next, %inner.backedge ]
+; CHECK-NEXT: --> {%outer.iv,+,1}<nuw><nsw><%inner> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
+; CHECK-NEXT: %iv.next = add nuw nsw i32 %iv, 1
+; CHECK-NEXT: --> {(1 + %outer.iv),+,1}<nw><%inner> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Computable, %outer: Variant }
+; CHECK-NEXT: %inner.loop.cond = call i1 @cond()
+; CHECK-NEXT: --> %inner.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %inner: Variant, %outer: Variant }
+; CHECK-NEXT: %outer.loop.cond = call i1 @cond()
+; CHECK-NEXT: --> %outer.loop.cond U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %outer: Variant, %inner: Invariant }
+; CHECK-NEXT: Determining loop execution counts for: @test_02
+; CHECK-NEXT: Loop %inner: <multiple exits> Unpredictable backedge-taken count.
+; CHECK-NEXT: exit count for inner: ((-1 * %outer.iv) + (%b smax %outer.iv))
+; CHECK-NEXT: exit count for inner.backedge: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: Loop %inner: max backedge-taken count is -1
+; CHECK-NEXT: Loop %inner: Unpredictable predicated backedge-taken count.
+; CHECK-NEXT: Loop %outer: <multiple exits> Unpredictable backedge-taken count.
+; CHECK-NEXT: exit count for inner: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: exit count for outer.backedge: ***COULDNOTCOMPUTE***
+; CHECK-NEXT: Loop %outer: Unpredictable max backedge-taken count.
+; CHECK-NEXT: Loop %outer: Unpredictable predicated backedge-taken count.
+;
+entry:
+ %b_is_non_negative = icmp sge i32 %b, 0
+ br i1 %b_is_non_negative, label %outer, label %failure
+
+outer:
+ %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge]
+ br label %inner
+
+inner:
+ %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge]
+ %signed_cond = icmp slt i32 %iv, %b
+ br i1 %signed_cond, label %inner.backedge, label %side.exit
+
+inner.backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %inner.loop.cond = call i1 @cond()
+ br i1 %inner.loop.cond, label %inner, label %outer.backedge
+
+outer.backedge:
+ %outer.loop.cond = call i1 @cond()
+ br i1 %outer.loop.cond, label %outer, label %exit
+
+failure:
+ unreachable
+
+side.exit:
+ ret i32 0
+
+exit:
+ ret i32 1
+}
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