[llvm] 958e7a2 - [Test] Add test showing missing opportunity in IndVar's handling of lshr
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Wed Dec 22 00:10:02 PST 2021
Author: Max Kazantsev
Date: 2021-12-22T15:08:22+07:00
New Revision: 958e7a284d1146842ee2b115172b5eed00e56649
URL: https://github.com/llvm/llvm-project/commit/958e7a284d1146842ee2b115172b5eed00e56649
DIFF: https://github.com/llvm/llvm-project/commit/958e7a284d1146842ee2b115172b5eed00e56649.diff
LOG: [Test] Add test showing missing opportunity in IndVar's handling of lshr
Added:
llvm/test/Transforms/IndVarSimplify/shift-range-checks.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/IndVarSimplify/shift-range-checks.ll b/llvm/test/Transforms/IndVarSimplify/shift-range-checks.ll
new file mode 100644
index 0000000000000..1dc91d105ab3c
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/shift-range-checks.ll
@@ -0,0 +1,244 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S < %s -indvars | FileCheck %s
+; RUN: opt -S < %s -passes=indvars | FileCheck %s
+
+declare i1 @cond()
+declare void @exit(i32 %code)
+
+; FIXME: We can remove 2nd check here because it is implied by check
+; against the shifted value.
+define void @test_01(i32* %p, i32 %shift) {
+; CHECK-LABEL: @test_01(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[X:%.*]] = load i32, i32* [[P:%.*]], align 4, !range [[RNG0:![0-9]+]]
+; CHECK-NEXT: [[X_SHIFTED:%.*]] = lshr i32 [[X]], [[SHIFT:%.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[LESS_THAN_SHIFTED:%.*]] = icmp slt i32 [[IV]], [[X_SHIFTED]]
+; CHECK-NEXT: br i1 [[LESS_THAN_SHIFTED]], label [[GUARDED:%.*]], label [[FAILURE:%.*]]
+; CHECK: guarded:
+; CHECK-NEXT: [[LESS_THAN_X:%.*]] = icmp ult i32 [[IV]], [[X]]
+; CHECK-NEXT: br i1 [[LESS_THAN_X]], label [[BACKEDGE]], label [[NEVER_HAPPENS:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond()
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]]
+; CHECK: done:
+; CHECK-NEXT: ret void
+; CHECK: failure:
+; CHECK-NEXT: call void @exit(i32 1)
+; CHECK-NEXT: unreachable
+; CHECK: never_happens:
+; CHECK-NEXT: call void @exit(i32 0)
+; CHECK-NEXT: unreachable
+;
+entry:
+ %x = load i32, i32* %p, !range !0
+ %x.shifted = lshr i32 %x, %shift
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+ %less.than.shifted = icmp slt i32 %iv, %x.shifted
+ br i1 %less.than.shifted, label %guarded, label %failure
+
+guarded:
+ %less.than.x = icmp slt i32 %iv, %x
+ br i1 %less.than.x, label %backedge, label %never_happens
+
+backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %loop.cond = call i1 @cond()
+ br i1 %loop.cond, label %loop, label %done
+
+done:
+ ret void
+
+failure:
+ call void @exit(i32 1)
+ unreachable
+
+never_happens:
+ call void @exit(i32 0)
+ unreachable
+}
+
+; FIXME: We can remove 2nd check here because it is implied by check
+; against the shifted value.
+define void @test_02(i32* %p, i32 %shift) {
+; CHECK-LABEL: @test_02(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[X:%.*]] = load i32, i32* [[P:%.*]], align 4, !range [[RNG0]]
+; CHECK-NEXT: [[X_SHIFTED:%.*]] = lshr i32 [[X]], [[SHIFT:%.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[LESS_THAN_SHIFTED:%.*]] = icmp sgt i32 [[X_SHIFTED]], [[IV]]
+; CHECK-NEXT: br i1 [[LESS_THAN_SHIFTED]], label [[GUARDED:%.*]], label [[FAILURE:%.*]]
+; CHECK: guarded:
+; CHECK-NEXT: [[LESS_THAN_X:%.*]] = icmp ugt i32 [[X]], [[IV]]
+; CHECK-NEXT: br i1 [[LESS_THAN_X]], label [[BACKEDGE]], label [[NEVER_HAPPENS:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond()
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]]
+; CHECK: done:
+; CHECK-NEXT: ret void
+; CHECK: failure:
+; CHECK-NEXT: call void @exit(i32 1)
+; CHECK-NEXT: unreachable
+; CHECK: never_happens:
+; CHECK-NEXT: call void @exit(i32 0)
+; CHECK-NEXT: unreachable
+;
+entry:
+ %x = load i32, i32* %p, !range !0
+ %x.shifted = lshr i32 %x, %shift
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+ %less.than.shifted = icmp sgt i32 %x.shifted, %iv
+ br i1 %less.than.shifted, label %guarded, label %failure
+
+guarded:
+ %less.than.x = icmp sgt i32 %x, %iv
+ br i1 %less.than.x, label %backedge, label %never_happens
+
+backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %loop.cond = call i1 @cond()
+ br i1 %loop.cond, label %loop, label %done
+
+done:
+ ret void
+
+failure:
+ call void @exit(i32 1)
+ unreachable
+
+never_happens:
+ call void @exit(i32 0)
+ unreachable
+}
+
+; FIXME: We can remove 2nd check here because it is implied by check
+; against the shifted value.
+define void @test_03(i32* %p, i32 %shift) {
+; CHECK-LABEL: @test_03(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[X:%.*]] = load i32, i32* [[P:%.*]], align 4, !range [[RNG0]]
+; CHECK-NEXT: [[X_SHIFTED:%.*]] = lshr i32 [[X]], [[SHIFT:%.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[LESS_THAN_SHIFTED:%.*]] = icmp ult i32 [[IV]], [[X_SHIFTED]]
+; CHECK-NEXT: br i1 [[LESS_THAN_SHIFTED]], label [[GUARDED:%.*]], label [[FAILURE:%.*]]
+; CHECK: guarded:
+; CHECK-NEXT: [[LESS_THAN_X:%.*]] = icmp ult i32 [[IV]], [[X]]
+; CHECK-NEXT: br i1 [[LESS_THAN_X]], label [[BACKEDGE]], label [[NEVER_HAPPENS:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond()
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]]
+; CHECK: done:
+; CHECK-NEXT: ret void
+; CHECK: failure:
+; CHECK-NEXT: call void @exit(i32 1)
+; CHECK-NEXT: unreachable
+; CHECK: never_happens:
+; CHECK-NEXT: call void @exit(i32 0)
+; CHECK-NEXT: unreachable
+;
+entry:
+ %x = load i32, i32* %p, !range !0
+ %x.shifted = lshr i32 %x, %shift
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+ %less.than.shifted = icmp ult i32 %iv, %x.shifted
+ br i1 %less.than.shifted, label %guarded, label %failure
+
+guarded:
+ %less.than.x = icmp ult i32 %iv, %x
+ br i1 %less.than.x, label %backedge, label %never_happens
+
+backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %loop.cond = call i1 @cond()
+ br i1 %loop.cond, label %loop, label %done
+
+done:
+ ret void
+
+failure:
+ call void @exit(i32 1)
+ unreachable
+
+never_happens:
+ call void @exit(i32 0)
+ unreachable
+}
+
+; FIXME: We can remove 2nd check here because it is implied by check
+; against the shifted value.
+define void @test_04(i32* %p, i32 %shift) {
+; CHECK-LABEL: @test_04(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[X:%.*]] = load i32, i32* [[P:%.*]], align 4, !range [[RNG0]]
+; CHECK-NEXT: [[X_SHIFTED:%.*]] = lshr i32 [[X]], [[SHIFT:%.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[LESS_THAN_SHIFTED:%.*]] = icmp ugt i32 [[X_SHIFTED]], [[IV]]
+; CHECK-NEXT: br i1 [[LESS_THAN_SHIFTED]], label [[GUARDED:%.*]], label [[FAILURE:%.*]]
+; CHECK: guarded:
+; CHECK-NEXT: [[LESS_THAN_X:%.*]] = icmp ugt i32 [[X]], [[IV]]
+; CHECK-NEXT: br i1 [[LESS_THAN_X]], label [[BACKEDGE]], label [[NEVER_HAPPENS:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT: [[LOOP_COND:%.*]] = call i1 @cond()
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]]
+; CHECK: done:
+; CHECK-NEXT: ret void
+; CHECK: failure:
+; CHECK-NEXT: call void @exit(i32 1)
+; CHECK-NEXT: unreachable
+; CHECK: never_happens:
+; CHECK-NEXT: call void @exit(i32 0)
+; CHECK-NEXT: unreachable
+;
+entry:
+ %x = load i32, i32* %p, !range !0
+ %x.shifted = lshr i32 %x, %shift
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+ %less.than.shifted = icmp ugt i32 %x.shifted, %iv
+ br i1 %less.than.shifted, label %guarded, label %failure
+
+guarded:
+ %less.than.x = icmp ugt i32 %x, %iv
+ br i1 %less.than.x, label %backedge, label %never_happens
+
+backedge:
+ %iv.next = add nuw nsw i32 %iv, 1
+ %loop.cond = call i1 @cond()
+ br i1 %loop.cond, label %loop, label %done
+
+done:
+ ret void
+
+failure:
+ call void @exit(i32 1)
+ unreachable
+
+never_happens:
+ call void @exit(i32 0)
+ unreachable
+}
+
+!0 = !{i32 0, i32 2147483647}
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