[llvm] ac90bbc - [LoopDeletion] Add test case where outer loop needs to be deleted.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 22 09:49:38 PST 2020
Author: Florian Hahn
Date: 2020-12-22T17:49:20Z
New Revision: ac90bbc9cb8b905e4a8e7c9d2924a4d426c690aa
URL: https://github.com/llvm/llvm-project/commit/ac90bbc9cb8b905e4a8e7c9d2924a4d426c690aa
DIFF: https://github.com/llvm/llvm-project/commit/ac90bbc9cb8b905e4a8e7c9d2924a4d426c690aa.diff
LOG: [LoopDeletion] Add test case where outer loop needs to be deleted.
In the test case @test1, the inner loop cannot be removed, because it
has a live-out value. But the outer loop is a no-op and can be removed.
Added:
llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll b/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
new file mode 100644
index 000000000000..464c12f453a7
--- /dev/null
+++ b/llvm/test/Transforms/LoopDeletion/noop-loops-with-subloops.ll
@@ -0,0 +1,172 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -loop-deletion -verify-dom-info -S | FileCheck %s
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64"
+
+%pair_t = type { i64, i64 }
+
+; The loop %inner cannot be removed, because it has outgoing values. But the
+; outer loop is a no-op and can be removed.
+define void @test1(i64 %N, i64 %M, %pair_t* %ptr) willreturn {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[OUTER_HEADER:%.*]]
+; CHECK: outer.header:
+; CHECK-NEXT: [[OUTER_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_IV_NEXT:%.*]], [[OUTER_LATCH:%.*]] ]
+; CHECK-NEXT: br label [[INNER:%.*]]
+; CHECK: inner:
+; CHECK-NEXT: [[INNER_IV:%.*]] = phi i64 [ 0, [[OUTER_HEADER]] ], [ [[INNER_IV_NEXT:%.*]], [[INNER]] ]
+; CHECK-NEXT: [[GEP:%.*]] = getelementptr [[PAIR_T:%.*]], %pair_t* [[PTR:%.*]], i64 [[INNER_IV]]
+; CHECK-NEXT: [[P:%.*]] = load [[PAIR_T]], %pair_t* [[GEP]], align 4
+; CHECK-NEXT: [[V_0:%.*]] = extractvalue [[PAIR_T]] [[P]], 0
+; CHECK-NEXT: [[V_1:%.*]] = extractvalue [[PAIR_T]] [[P]], 1
+; CHECK-NEXT: [[INNER_EC:%.*]] = icmp ult i64 [[V_0]], [[V_1]]
+; CHECK-NEXT: [[INNER_IV_NEXT]] = add i64 [[INNER_IV]], 1
+; CHECK-NEXT: br i1 [[INNER_EC]], label [[OUTER_LATCH]], label [[INNER]]
+; CHECK: outer.latch:
+; CHECK-NEXT: [[LCSSA:%.*]] = phi i64 [ [[V_1]], [[INNER]] ]
+; CHECK-NEXT: [[OUTER_EC:%.*]] = icmp ult i64 [[OUTER_IV]], [[LCSSA]]
+; CHECK-NEXT: [[OUTER_IV_NEXT]] = add i64 [[OUTER_IV]], 1
+; CHECK-NEXT: br i1 [[OUTER_EC]], label [[EXIT:%.*]], label [[OUTER_HEADER]]
+; CHECK: exit:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %outer.header
+
+outer.header:
+ %outer.iv = phi i64 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
+
+ br label %inner
+
+inner:
+ %inner.iv = phi i64 [ 0, %outer.header ], [ %inner.iv.next, %inner ]
+ %gep = getelementptr %pair_t, %pair_t* %ptr, i64 %inner.iv
+ %p = load %pair_t, %pair_t* %gep
+ %v.0 = extractvalue %pair_t %p, 0
+ %v.1 = extractvalue %pair_t %p, 1
+ %inner.ec = icmp ult i64 %v.0, %v.1
+ %inner.iv.next = add i64 %inner.iv, 1
+ br i1 %inner.ec, label %outer.latch, label %inner
+
+outer.latch:
+ %lcssa = phi i64 [ %v.1, %inner ]
+ %outer.ec = icmp ult i64 %outer.iv, %lcssa
+ %outer.iv.next = add i64 %outer.iv, 1
+ br i1 %outer.ec, label %exit, label %outer.header
+
+exit:
+ ret void
+}
+
+declare void @sideeffect()
+
+; Same as @test1, but with a call in the outer loop. Nothing can be deleted.
+define void @test2_sideeffect_in_outer(i64 %N, i64 %M, %pair_t* %ptr) willreturn {
+; CHECK-LABEL: @test2_sideeffect_in_outer(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[OUTER_HEADER:%.*]]
+; CHECK: outer.header:
+; CHECK-NEXT: [[OUTER_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_IV_NEXT:%.*]], [[OUTER_LATCH:%.*]] ]
+; CHECK-NEXT: br label [[INNER:%.*]]
+; CHECK: inner:
+; CHECK-NEXT: [[INNER_IV:%.*]] = phi i64 [ 0, [[OUTER_HEADER]] ], [ [[INNER_IV_NEXT:%.*]], [[INNER]] ]
+; CHECK-NEXT: [[GEP:%.*]] = getelementptr [[PAIR_T:%.*]], %pair_t* [[PTR:%.*]], i64 [[INNER_IV]]
+; CHECK-NEXT: [[P:%.*]] = load [[PAIR_T]], %pair_t* [[GEP]], align 4
+; CHECK-NEXT: [[V_0:%.*]] = extractvalue [[PAIR_T]] [[P]], 0
+; CHECK-NEXT: [[V_1:%.*]] = extractvalue [[PAIR_T]] [[P]], 1
+; CHECK-NEXT: [[INNER_EC:%.*]] = icmp ult i64 [[V_0]], [[V_1]]
+; CHECK-NEXT: [[INNER_IV_NEXT]] = add i64 [[INNER_IV]], 1
+; CHECK-NEXT: br i1 [[INNER_EC]], label [[OUTER_LATCH]], label [[INNER]]
+; CHECK: outer.latch:
+; CHECK-NEXT: [[LCSSA:%.*]] = phi i64 [ [[V_1]], [[INNER]] ]
+; CHECK-NEXT: [[OUTER_EC:%.*]] = icmp ult i64 [[OUTER_IV]], [[LCSSA]]
+; CHECK-NEXT: [[OUTER_IV_NEXT]] = add i64 [[OUTER_IV]], 1
+; CHECK-NEXT: call void @sideeffect()
+; CHECK-NEXT: br i1 [[OUTER_EC]], label [[EXIT:%.*]], label [[OUTER_HEADER]]
+; CHECK: exit:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %outer.header
+
+outer.header:
+ %outer.iv = phi i64 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
+
+ br label %inner
+
+inner:
+ %inner.iv = phi i64 [ 0, %outer.header ], [ %inner.iv.next, %inner ]
+ %gep = getelementptr %pair_t, %pair_t* %ptr, i64 %inner.iv
+ %p = load %pair_t, %pair_t* %gep
+ %v.0 = extractvalue %pair_t %p, 0
+ %v.1 = extractvalue %pair_t %p, 1
+ %inner.ec = icmp ult i64 %v.0, %v.1
+ %inner.iv.next = add i64 %inner.iv, 1
+ br i1 %inner.ec, label %outer.latch, label %inner
+
+outer.latch:
+ %lcssa = phi i64 [ %v.1, %inner ]
+ %outer.ec = icmp ult i64 %outer.iv, %lcssa
+ %outer.iv.next = add i64 %outer.iv, 1
+ call void @sideeffect()
+ br i1 %outer.ec, label %exit, label %outer.header
+
+exit:
+ ret void
+}
+
+; Same as @test1, but with a call in the inner loop. Nothing can be deleted.
+define void @test3_sideeffect_in_inner(i64 %N, i64 %M, %pair_t* %ptr) willreturn {
+; CHECK-LABEL: @test3_sideeffect_in_inner(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[OUTER_HEADER:%.*]]
+; CHECK: outer.header:
+; CHECK-NEXT: [[OUTER_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_IV_NEXT:%.*]], [[OUTER_LATCH:%.*]] ]
+; CHECK-NEXT: br label [[INNER:%.*]]
+; CHECK: inner:
+; CHECK-NEXT: [[INNER_IV:%.*]] = phi i64 [ 0, [[OUTER_HEADER]] ], [ [[INNER_IV_NEXT:%.*]], [[INNER]] ]
+; CHECK-NEXT: [[GEP:%.*]] = getelementptr [[PAIR_T:%.*]], %pair_t* [[PTR:%.*]], i64 [[INNER_IV]]
+; CHECK-NEXT: [[P:%.*]] = load [[PAIR_T]], %pair_t* [[GEP]], align 4
+; CHECK-NEXT: [[V_0:%.*]] = extractvalue [[PAIR_T]] [[P]], 0
+; CHECK-NEXT: [[V_1:%.*]] = extractvalue [[PAIR_T]] [[P]], 1
+; CHECK-NEXT: [[INNER_EC:%.*]] = icmp ult i64 [[V_0]], [[V_1]]
+; CHECK-NEXT: [[INNER_IV_NEXT]] = add i64 [[INNER_IV]], 1
+; CHECK-NEXT: call void @sideeffect()
+; CHECK-NEXT: br i1 [[INNER_EC]], label [[OUTER_LATCH]], label [[INNER]]
+; CHECK: outer.latch:
+; CHECK-NEXT: [[LCSSA:%.*]] = phi i64 [ [[V_1]], [[INNER]] ]
+; CHECK-NEXT: [[OUTER_EC:%.*]] = icmp ult i64 [[OUTER_IV]], [[LCSSA]]
+; CHECK-NEXT: [[OUTER_IV_NEXT]] = add i64 [[OUTER_IV]], 1
+; CHECK-NEXT: br i1 [[OUTER_EC]], label [[EXIT:%.*]], label [[OUTER_HEADER]]
+; CHECK: exit:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %outer.header
+
+outer.header:
+ %outer.iv = phi i64 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
+
+ br label %inner
+
+inner:
+ %inner.iv = phi i64 [ 0, %outer.header ], [ %inner.iv.next, %inner ]
+ %gep = getelementptr %pair_t, %pair_t* %ptr, i64 %inner.iv
+ %p = load %pair_t, %pair_t* %gep
+ %v.0 = extractvalue %pair_t %p, 0
+ %v.1 = extractvalue %pair_t %p, 1
+ %inner.ec = icmp ult i64 %v.0, %v.1
+ %inner.iv.next = add i64 %inner.iv, 1
+ call void @sideeffect()
+ br i1 %inner.ec, label %outer.latch, label %inner
+
+outer.latch:
+ %lcssa = phi i64 [ %v.1, %inner ]
+ %outer.ec = icmp ult i64 %outer.iv, %lcssa
+ %outer.iv.next = add i64 %outer.iv, 1
+ br i1 %outer.ec, label %exit, label %outer.header
+
+exit:
+ ret void
+}
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