llvm-project/llvm/test/Transforms/SimpleLoopUnswitch/trivial-unswitch.ll

446 lines
12 KiB
LLVM

; RUN: opt -passes='loop(unswitch),verify<loops>' -S < %s | FileCheck %s
declare void @some_func() noreturn
; This test contains two trivial unswitch condition in one loop.
; LoopUnswitch pass should be able to unswitch the second one
; after unswitching the first one.
define i32 @test1(i32* %var, i1 %cond1, i1 %cond2) {
; CHECK-LABEL: @test1(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %{{.*}}, label %entry.split, label %loop_exit.split
;
; CHECK: entry.split:
; CHECK-NEXT: br i1 %{{.*}}, label %entry.split.split, label %loop_exit
;
; CHECK: entry.split.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
br i1 %cond1, label %continue, label %loop_exit ; first trivial condition
; CHECK: loop_begin:
; CHECK-NEXT: br label %continue
continue:
%var_val = load i32, i32* %var
br i1 %cond2, label %do_something, label %loop_exit ; second trivial condition
; CHECK: continue:
; CHECK-NEXT: load
; CHECK-NEXT: br label %do_something
do_something:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: do_something:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit:
ret i32 0
; CHECK: loop_exit:
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: ret
}
; Test for two trivially unswitchable switches.
define i32 @test3(i32* %var, i32 %cond1, i32 %cond2) {
; CHECK-LABEL: @test3(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond1, label %entry.split [
; CHECK-NEXT: i32 0, label %loop_exit1
; CHECK-NEXT: ]
;
; CHECK: entry.split:
; CHECK-NEXT: switch i32 %cond2, label %loop_exit2 [
; CHECK-NEXT: i32 42, label %loop_exit2
; CHECK-NEXT: i32 0, label %entry.split.split
; CHECK-NEXT: ]
;
; CHECK: entry.split.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
switch i32 %cond1, label %continue [
i32 0, label %loop_exit1
]
; CHECK: loop_begin:
; CHECK-NEXT: br label %continue
continue:
%var_val = load i32, i32* %var
switch i32 %cond2, label %loop_exit2 [
i32 0, label %do_something
i32 42, label %loop_exit2
]
; CHECK: continue:
; CHECK-NEXT: load
; CHECK-NEXT: br label %do_something
do_something:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: do_something:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit1:
ret i32 0
; CHECK: loop_exit1:
; CHECK-NEXT: ret
loop_exit2:
ret i32 0
; CHECK: loop_exit2:
; CHECK-NEXT: ret
;
; We shouldn't have any unreachable blocks here because the unswitched switches
; turn into branches instead.
; CHECK-NOT: unreachable
}
; Test for a trivially unswitchable switch with multiple exiting cases and
; multiple looping cases.
define i32 @test4(i32* %var, i32 %cond1, i32 %cond2) {
; CHECK-LABEL: @test4(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond2, label %loop_exit2 [
; CHECK-NEXT: i32 13, label %loop_exit1
; CHECK-NEXT: i32 42, label %loop_exit3
; CHECK-NEXT: i32 0, label %entry.split
; CHECK-NEXT: i32 1, label %entry.split
; CHECK-NEXT: i32 2, label %entry.split
; CHECK-NEXT: ]
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
%var_val = load i32, i32* %var
switch i32 %cond2, label %loop_exit2 [
i32 0, label %loop0
i32 1, label %loop1
i32 13, label %loop_exit1
i32 2, label %loop2
i32 42, label %loop_exit3
]
; CHECK: loop_begin:
; CHECK-NEXT: load
; CHECK-NEXT: switch i32 %cond2, label %[[UNREACHABLE:.*]] [
; CHECK-NEXT: i32 0, label %loop0
; CHECK-NEXT: i32 1, label %loop1
; CHECK-NEXT: i32 2, label %loop2
; CHECK-NEXT: ]
loop0:
call void @some_func() noreturn nounwind
br label %loop_latch
; CHECK: loop0:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_latch
loop1:
call void @some_func() noreturn nounwind
br label %loop_latch
; CHECK: loop1:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_latch
loop2:
call void @some_func() noreturn nounwind
br label %loop_latch
; CHECK: loop2:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_latch
loop_latch:
br label %loop_begin
; CHECK: loop_latch:
; CHECK-NEXT: br label %loop_begin
loop_exit1:
ret i32 0
; CHECK: loop_exit1:
; CHECK-NEXT: ret
loop_exit2:
ret i32 0
; CHECK: loop_exit2:
; CHECK-NEXT: ret
loop_exit3:
ret i32 0
; CHECK: loop_exit3:
; CHECK-NEXT: ret
;
; CHECK: [[UNREACHABLE]]:
; CHECK-NEXT: unreachable
}
; This test contains a trivially unswitchable branch with an LCSSA phi node in
; a loop exit block.
define i32 @test5(i1 %cond1, i32 %x, i32 %y) {
; CHECK-LABEL: @test5(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %{{.*}}, label %entry.split, label %loop_exit
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
br i1 %cond1, label %latch, label %loop_exit
; CHECK: loop_begin:
; CHECK-NEXT: br label %latch
latch:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: latch:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit:
%result1 = phi i32 [ %x, %loop_begin ]
%result2 = phi i32 [ %y, %loop_begin ]
%result = add i32 %result1, %result2
ret i32 %result
; CHECK: loop_exit:
; CHECK-NEXT: %[[R1:.*]] = phi i32 [ %x, %entry ]
; CHECK-NEXT: %[[R2:.*]] = phi i32 [ %y, %entry ]
; CHECK-NEXT: %[[R:.*]] = add i32 %[[R1]], %[[R2]]
; CHECK-NEXT: ret i32 %[[R]]
}
; This test contains a trivially unswitchable branch with a real phi node in LCSSA
; position in a shared exit block where a different path through the loop
; produces a non-invariant input to the PHI node.
define i32 @test6(i32* %var, i1 %cond1, i1 %cond2, i32 %x, i32 %y) {
; CHECK-LABEL: @test6(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %{{.*}}, label %entry.split, label %loop_exit.split
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
br i1 %cond1, label %continue, label %loop_exit
; CHECK: loop_begin:
; CHECK-NEXT: br label %continue
continue:
%var_val = load i32, i32* %var
br i1 %cond2, label %latch, label %loop_exit
; CHECK: continue:
; CHECK-NEXT: load
; CHECK-NEXT: br i1 %cond2, label %latch, label %loop_exit
latch:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: latch:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit:
%result1 = phi i32 [ %x, %loop_begin ], [ %var_val, %continue ]
%result2 = phi i32 [ %var_val, %continue ], [ %y, %loop_begin ]
%result = add i32 %result1, %result2
ret i32 %result
; CHECK: loop_exit:
; CHECK-NEXT: %[[R1:.*]] = phi i32 [ %var_val, %continue ]
; CHECK-NEXT: %[[R2:.*]] = phi i32 [ %var_val, %continue ]
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[R1S:.*]] = phi i32 [ %x, %entry ], [ %[[R1]], %loop_exit ]
; CHECK-NEXT: %[[R2S:.*]] = phi i32 [ %y, %entry ], [ %[[R2]], %loop_exit ]
; CHECK-NEXT: %[[R:.*]] = add i32 %[[R1S]], %[[R2S]]
; CHECK-NEXT: ret i32 %[[R]]
}
; This test contains a trivially unswitchable switch with an LCSSA phi node in
; a loop exit block.
define i32 @test7(i32 %cond1, i32 %x, i32 %y) {
; CHECK-LABEL: @test7(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond1, label %entry.split [
; CHECK-NEXT: i32 0, label %loop_exit
; CHECK-NEXT: i32 1, label %loop_exit
; CHECK-NEXT: ]
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
switch i32 %cond1, label %latch [
i32 0, label %loop_exit
i32 1, label %loop_exit
]
; CHECK: loop_begin:
; CHECK-NEXT: br label %latch
latch:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: latch:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit:
%result1 = phi i32 [ %x, %loop_begin ], [ %x, %loop_begin ]
%result2 = phi i32 [ %y, %loop_begin ], [ %y, %loop_begin ]
%result = add i32 %result1, %result2
ret i32 %result
; CHECK: loop_exit:
; CHECK-NEXT: %[[R1:.*]] = phi i32 [ %x, %entry ], [ %x, %entry ]
; CHECK-NEXT: %[[R2:.*]] = phi i32 [ %y, %entry ], [ %y, %entry ]
; CHECK-NEXT: %[[R:.*]] = add i32 %[[R1]], %[[R2]]
; CHECK-NEXT: ret i32 %[[R]]
}
; This test contains a trivially unswitchable switch with a real phi node in
; LCSSA position in a shared exit block where a different path through the loop
; produces a non-invariant input to the PHI node.
define i32 @test8(i32* %var, i32 %cond1, i32 %cond2, i32 %x, i32 %y) {
; CHECK-LABEL: @test8(
entry:
br label %loop_begin
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 %cond1, label %entry.split [
; CHECK-NEXT: i32 0, label %loop_exit.split
; CHECK-NEXT: i32 1, label %loop_exit2
; CHECK-NEXT: i32 2, label %loop_exit.split
; CHECK-NEXT: ]
;
; CHECK: entry.split:
; CHECK-NEXT: br label %loop_begin
loop_begin:
switch i32 %cond1, label %continue [
i32 0, label %loop_exit
i32 1, label %loop_exit2
i32 2, label %loop_exit
]
; CHECK: loop_begin:
; CHECK-NEXT: br label %continue
continue:
%var_val = load i32, i32* %var
switch i32 %cond2, label %latch [
i32 0, label %loop_exit
]
; CHECK: continue:
; CHECK-NEXT: load
; CHECK-NEXT: switch i32 %cond2, label %latch [
; CHECK-NEXT: i32 0, label %loop_exit
; CHECK-NEXT: ]
latch:
call void @some_func() noreturn nounwind
br label %loop_begin
; CHECK: latch:
; CHECK-NEXT: call
; CHECK-NEXT: br label %loop_begin
loop_exit:
%result1.1 = phi i32 [ %x, %loop_begin ], [ %x, %loop_begin ], [ %var_val, %continue ]
%result1.2 = phi i32 [ %var_val, %continue ], [ %y, %loop_begin ], [ %y, %loop_begin ]
%result1 = add i32 %result1.1, %result1.2
ret i32 %result1
; CHECK: loop_exit:
; CHECK-NEXT: %[[R1:.*]] = phi i32 [ %var_val, %continue ]
; CHECK-NEXT: %[[R2:.*]] = phi i32 [ %var_val, %continue ]
; CHECK-NEXT: br label %loop_exit.split
;
; CHECK: loop_exit.split:
; CHECK-NEXT: %[[R1S:.*]] = phi i32 [ %x, %entry ], [ %x, %entry ], [ %[[R1]], %loop_exit ]
; CHECK-NEXT: %[[R2S:.*]] = phi i32 [ %y, %entry ], [ %y, %entry ], [ %[[R2]], %loop_exit ]
; CHECK-NEXT: %[[R:.*]] = add i32 %[[R1S]], %[[R2S]]
; CHECK-NEXT: ret i32 %[[R]]
loop_exit2:
%result2.1 = phi i32 [ %x, %loop_begin ]
%result2.2 = phi i32 [ %y, %loop_begin ]
%result2 = add i32 %result2.1, %result2.2
ret i32 %result2
; CHECK: loop_exit2:
; CHECK-NEXT: %[[R1:.*]] = phi i32 [ %x, %entry ]
; CHECK-NEXT: %[[R2:.*]] = phi i32 [ %y, %entry ]
; CHECK-NEXT: %[[R:.*]] = add i32 %[[R1]], %[[R2]]
; CHECK-NEXT: ret i32 %[[R]]
}
; This test, extracted from the LLVM test suite, has an interesting dominator
; tree to update as there are edges to sibling domtree nodes within child
; domtree nodes of the unswitched node.
define void @xgets(i1 %cond1, i1* %cond2.ptr) {
; CHECK-LABEL: @xgets(
entry:
br label %for.cond.preheader
; CHECK: entry:
; CHECK-NEXT: br label %for.cond.preheader
for.cond.preheader:
br label %for.cond
; CHECK: for.cond.preheader:
; CHECK-NEXT: br i1 %cond1, label %for.cond.preheader.split, label %if.end17.thread.loopexit
;
; CHECK: for.cond.preheader.split:
; CHECK-NEXT: br label %for.cond
for.cond:
br i1 %cond1, label %land.lhs.true, label %if.end17.thread.loopexit
; CHECK: for.cond:
; CHECK-NEXT: br label %land.lhs.true
land.lhs.true:
br label %if.then20
; CHECK: land.lhs.true:
; CHECK-NEXT: br label %if.then20
if.then20:
%cond2 = load volatile i1, i1* %cond2.ptr
br i1 %cond2, label %if.then23, label %if.else
; CHECK: if.then20:
; CHECK-NEXT: %[[COND2:.*]] = load volatile i1, i1* %cond2.ptr
; CHECK-NEXT: br i1 %[[COND2]], label %if.then23, label %if.else
if.else:
br label %for.cond
; CHECK: if.else:
; CHECK-NEXT: br label %for.cond
if.end17.thread.loopexit:
br label %if.end17.thread
; CHECK: if.end17.thread.loopexit:
; CHECK-NEXT: br label %if.end17.thread
if.end17.thread:
br label %cleanup
; CHECK: if.end17.thread:
; CHECK-NEXT: br label %cleanup
if.then23:
br label %cleanup
; CHECK: if.then23:
; CHECK-NEXT: br label %cleanup
cleanup:
ret void
; CHECK: cleanup:
; CHECK-NEXT: ret void
}