188 lines
6.6 KiB
LLVM
188 lines
6.6 KiB
LLVM
; RUN: opt -passes='print<scalar-evolution>,loop(unswitch<nontrivial>,loop-instsimplify),print<scalar-evolution>' -S < %s 2>%t.scev | FileCheck %s
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; RUN: opt -verify-memoryssa -passes='print<scalar-evolution>,loop-mssa(unswitch<nontrivial>,loop-instsimplify),print<scalar-evolution>' -S < %s 2>%t.scev | FileCheck %s
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; RUN: FileCheck %s --check-prefix=SCEV < %t.scev
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target triple = "x86_64-unknown-linux-gnu"
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declare void @f()
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; Check that trivially unswitching an inner loop resets both the inner and outer
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; loop trip count.
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define void @test1(i32 %n, i32 %m, i1 %cond) {
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; Check that SCEV has no trip count before unswitching.
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; SCEV-LABEL: Determining loop execution counts for: @test1
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; SCEV: Loop %inner_loop_begin: <multiple exits> Unpredictable backedge-taken count.
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; SCEV: Loop %outer_loop_begin: Unpredictable backedge-taken count.
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;
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; Now check that after unswitching and simplifying instructions we get clean
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; backedge-taken counts.
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; SCEV-LABEL: Determining loop execution counts for: @test1
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; SCEV: Loop %inner_loop_begin: backedge-taken count is (-1 + (1 smax %m))<nsw>
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; SCEV: Loop %outer_loop_begin: backedge-taken count is (-1 + (1 smax %n))<nsw>
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;
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; And verify the code matches what we expect.
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; CHECK-LABEL: define void @test1(
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entry:
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br label %outer_loop_begin
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; Ensure the outer loop didn't get unswitched.
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; CHECK: entry:
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; CHECK-NEXT: br label %outer_loop_begin
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outer_loop_begin:
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%i = phi i32 [ %i.next, %outer_loop_latch ], [ 0, %entry ]
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; Block unswitching of the outer loop with a noduplicate call.
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call void @f() noduplicate
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br label %inner_loop_begin
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; Ensure the inner loop got unswitched into the outer loop.
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; CHECK: outer_loop_begin:
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; CHECK-NEXT: %{{.*}} = phi i32
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; CHECK-NEXT: call void @f()
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; CHECK-NEXT: br i1 %cond,
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inner_loop_begin:
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%j = phi i32 [ %j.next, %inner_loop_latch ], [ 0, %outer_loop_begin ]
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br i1 %cond, label %inner_loop_latch, label %inner_loop_early_exit
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inner_loop_latch:
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%j.next = add nsw i32 %j, 1
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%j.cmp = icmp slt i32 %j.next, %m
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br i1 %j.cmp, label %inner_loop_begin, label %inner_loop_late_exit
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inner_loop_early_exit:
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%j.lcssa = phi i32 [ %i, %inner_loop_begin ]
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br label %outer_loop_latch
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inner_loop_late_exit:
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br label %outer_loop_latch
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outer_loop_latch:
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%i.phi = phi i32 [ %j.lcssa, %inner_loop_early_exit ], [ %i, %inner_loop_late_exit ]
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%i.next = add nsw i32 %i.phi, 1
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%i.cmp = icmp slt i32 %i.next, %n
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br i1 %i.cmp, label %outer_loop_begin, label %exit
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exit:
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ret void
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}
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; Check that trivially unswitching an inner loop resets both the inner and outer
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; loop trip count.
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define void @test2(i32 %n, i32 %m, i32 %cond) {
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; Check that SCEV has no trip count before unswitching.
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; SCEV-LABEL: Determining loop execution counts for: @test2
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; SCEV: Loop %inner_loop_begin: <multiple exits> Unpredictable backedge-taken count.
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; SCEV: Loop %outer_loop_begin: Unpredictable backedge-taken count.
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;
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; Now check that after unswitching and simplifying instructions we get clean
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; backedge-taken counts.
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; SCEV-LABEL: Determining loop execution counts for: @test2
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; SCEV: Loop %inner_loop_begin: backedge-taken count is (-1 + (1 smax %m))<nsw>
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; SCEV: Loop %outer_loop_begin: backedge-taken count is (-1 + (1 smax %n))<nsw>
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;
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; CHECK-LABEL: define void @test2(
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entry:
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br label %outer_loop_begin
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; Ensure the outer loop didn't get unswitched.
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; CHECK: entry:
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; CHECK-NEXT: br label %outer_loop_begin
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outer_loop_begin:
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%i = phi i32 [ %i.next, %outer_loop_latch ], [ 0, %entry ]
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; Block unswitching of the outer loop with a noduplicate call.
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call void @f() noduplicate
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br label %inner_loop_begin
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; Ensure the inner loop got unswitched into the outer loop.
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; CHECK: outer_loop_begin:
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; CHECK-NEXT: %{{.*}} = phi i32
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; CHECK-NEXT: call void @f()
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; CHECK-NEXT: switch i32 %cond,
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inner_loop_begin:
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%j = phi i32 [ %j.next, %inner_loop_latch ], [ 0, %outer_loop_begin ]
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switch i32 %cond, label %inner_loop_early_exit [
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i32 1, label %inner_loop_latch
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i32 2, label %inner_loop_latch
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]
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inner_loop_latch:
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%j.next = add nsw i32 %j, 1
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%j.cmp = icmp slt i32 %j.next, %m
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br i1 %j.cmp, label %inner_loop_begin, label %inner_loop_late_exit
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inner_loop_early_exit:
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%j.lcssa = phi i32 [ %i, %inner_loop_begin ]
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br label %outer_loop_latch
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inner_loop_late_exit:
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br label %outer_loop_latch
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outer_loop_latch:
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%i.phi = phi i32 [ %j.lcssa, %inner_loop_early_exit ], [ %i, %inner_loop_late_exit ]
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%i.next = add nsw i32 %i.phi, 1
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%i.cmp = icmp slt i32 %i.next, %n
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br i1 %i.cmp, label %outer_loop_begin, label %exit
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exit:
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ret void
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}
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; Check that non-trivial unswitching of a branch in an inner loop into the outer
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; loop invalidates both inner and outer.
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define void @test3(i32 %n, i32 %m, i1 %cond) {
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; Check that SCEV has no trip count before unswitching.
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; SCEV-LABEL: Determining loop execution counts for: @test3
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; SCEV: Loop %inner_loop_begin: <multiple exits> Unpredictable backedge-taken count.
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; SCEV: Loop %outer_loop_begin: Unpredictable backedge-taken count.
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;
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; Now check that after unswitching and simplifying instructions we get clean
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; backedge-taken counts.
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; SCEV-LABEL: Determining loop execution counts for: @test3
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; SCEV: Loop %inner_loop_begin{{.*}}: backedge-taken count is (-1 + (1 smax %m))<nsw>
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; SCEV: Loop %outer_loop_begin: backedge-taken count is (-1 + (1 smax %n))<nsw>
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;
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; And verify the code matches what we expect.
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; CHECK-LABEL: define void @test3(
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entry:
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br label %outer_loop_begin
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; Ensure the outer loop didn't get unswitched.
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; CHECK: entry:
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; CHECK-NEXT: br label %outer_loop_begin
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outer_loop_begin:
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%i = phi i32 [ %i.next, %outer_loop_latch ], [ 0, %entry ]
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; Block unswitching of the outer loop with a noduplicate call.
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call void @f() noduplicate
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br label %inner_loop_begin
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; Ensure the inner loop got unswitched into the outer loop.
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; CHECK: outer_loop_begin:
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; CHECK-NEXT: %{{.*}} = phi i32
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; CHECK-NEXT: call void @f()
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; CHECK-NEXT: br i1 %cond,
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inner_loop_begin:
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%j = phi i32 [ %j.next, %inner_loop_latch ], [ 0, %outer_loop_begin ]
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%j.tmp = add nsw i32 %j, 1
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br i1 %cond, label %inner_loop_latch, label %inner_loop_early_exit
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inner_loop_latch:
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%j.next = add nsw i32 %j, 1
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%j.cmp = icmp slt i32 %j.next, %m
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br i1 %j.cmp, label %inner_loop_begin, label %inner_loop_late_exit
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inner_loop_early_exit:
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%j.lcssa = phi i32 [ %j.tmp, %inner_loop_begin ]
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br label %outer_loop_latch
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inner_loop_late_exit:
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br label %outer_loop_latch
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outer_loop_latch:
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%inc.phi = phi i32 [ %j.lcssa, %inner_loop_early_exit ], [ 1, %inner_loop_late_exit ]
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%i.next = add nsw i32 %i, %inc.phi
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%i.cmp = icmp slt i32 %i.next, %n
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br i1 %i.cmp, label %outer_loop_begin, label %exit
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exit:
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ret void
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}
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