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 +} _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
