ret i32 %b
}
+define i32 @test_loop_cold_blocks(i32 %i, i32* %a) {
+; Check that we sink cold loop blocks after the hot loop body.
+; CHECK: test_loop_cold_blocks:
+; CHECK: %entry
+; CHECK: %body1
+; CHECK: %body2
+; CHECK: %body3
+; CHECK: %unlikely1
+; CHECK: %unlikely2
+; CHECK: %exit
+
+entry:
+ br label %body1
+
+body1:
+ %iv = phi i32 [ 0, %entry ], [ %next, %body3 ]
+ %base = phi i32 [ 0, %entry ], [ %sum, %body3 ]
+ %unlikelycond1 = icmp slt i32 %base, 42
+ br i1 %unlikelycond1, label %unlikely1, label %body2, !prof !0
+
+unlikely1:
+ call void @error(i32 %i, i32 1, i32 %base)
+ br label %body2
+
+body2:
+ %unlikelycond2 = icmp sgt i32 %base, 21
+ br i1 %unlikelycond2, label %unlikely2, label %body3, !prof !0
+
+unlikely2:
+ call void @error(i32 %i, i32 2, i32 %base)
+ br label %body3
+
+body3:
+ %arrayidx = getelementptr inbounds i32* %a, i32 %iv
+ %0 = load i32* %arrayidx
+ %sum = add nsw i32 %0, %base
+ %next = add i32 %iv, 1
+ %exitcond = icmp eq i32 %next, %i
+ br i1 %exitcond, label %exit, label %body1
+
+exit:
+ ret i32 %sum
+}
+
!0 = metadata !{metadata !"branch_weights", i32 4, i32 64}
+define i32 @test_loop_early_exits(i32 %i, i32* %a) {
+; Check that we sink early exit blocks out of loop bodies.
+; CHECK: test_loop_early_exits:
+; CHECK: %entry
+; CHECK: %body1
+; CHECK: %body2
+; CHECK: %body3
+; CHECK: %body4
+; CHECK: %exit
+; CHECK: %bail1
+; CHECK: %bail2
+; CHECK: %bail3
+
+entry:
+ br label %body1
+
+body1:
+ %iv = phi i32 [ 0, %entry ], [ %next, %body4 ]
+ %base = phi i32 [ 0, %entry ], [ %sum, %body4 ]
+ %bailcond1 = icmp eq i32 %base, 42
+ br i1 %bailcond1, label %bail1, label %body2
+
+bail1:
+ ret i32 -1
+
+body2:
+ %bailcond2 = icmp eq i32 %base, 43
+ br i1 %bailcond2, label %bail2, label %body3
+
+bail2:
+ ret i32 -2
+
+body3:
+ %bailcond3 = icmp eq i32 %base, 44
+ br i1 %bailcond3, label %bail3, label %body4
+
+bail3:
+ ret i32 -3
+
+body4:
+ %arrayidx = getelementptr inbounds i32* %a, i32 %iv
+ %0 = load i32* %arrayidx
+ %sum = add nsw i32 %0, %base
+ %next = add i32 %iv, 1
+ %exitcond = icmp eq i32 %next, %i
+ br i1 %exitcond, label %exit, label %body1
+
+exit:
+ ret i32 %sum
+}
+
define i32 @test_loop_align(i32 %i, i32* %a) {
; Check that we provide basic loop body alignment with the block placement
; pass.
; CHECK: test_loop_align:
; CHECK: %entry
-; CHECK: .align 16,
+; CHECK: .align [[ALIGN:[0-9]+]],
; CHECK-NEXT: %body
; CHECK: %exit
; Check that we provide nested loop body alignment.
; CHECK: test_nested_loop_align:
; CHECK: %entry
-; CHECK: .align 16,
+; CHECK: .align [[ALIGN]],
; CHECK-NEXT: %loop.body.1
-; CHECK: .align 16,
+; CHECK: .align [[ALIGN]],
; CHECK-NEXT: %inner.loop.body
; CHECK-NOT: .align
-; CHECK: %loop.body.2
; CHECK: %exit
entry:
exit:
ret i32 %sum
}
+
+define void @unnatural_cfg1() {
+; Test that we can handle a loop with an inner unnatural loop at the end of
+; a function. This is a gross CFG reduced out of the single source GCC.
+; CHECK: unnatural_cfg1
+; CHECK: %entry
+; CHECK: %loop.body1
+; CHECK: %loop.body2
+; CHECK: %loop.body3
+
+entry:
+ br label %loop.header
+
+loop.header:
+ br label %loop.body1
+
+loop.body1:
+ br i1 undef, label %loop.body3, label %loop.body2
+
+loop.body2:
+ %ptr = load i32** undef, align 4
+ br label %loop.body3
+
+loop.body3:
+ %myptr = phi i32* [ %ptr2, %loop.body5 ], [ %ptr, %loop.body2 ], [ undef, %loop.body1 ]
+ %bcmyptr = bitcast i32* %myptr to i32*
+ %val = load i32* %bcmyptr, align 4
+ %comp = icmp eq i32 %val, 48
+ br i1 %comp, label %loop.body4, label %loop.body5
+
+loop.body4:
+ br i1 undef, label %loop.header, label %loop.body5
+
+loop.body5:
+ %ptr2 = load i32** undef, align 4
+ br label %loop.body3
+}
+
+define void @unnatural_cfg2() {
+; Test that we can handle a loop with a nested natural loop *and* an unnatural
+; loop. This was reduced from a crash on block placement when run over
+; single-source GCC.
+; CHECK: unnatural_cfg2
+; CHECK: %entry
+; CHECK: %loop.header
+; CHECK: %loop.body1
+; CHECK: %loop.body2
+; CHECK: %loop.body3
+; CHECK: %loop.inner1.begin
+; The end block is folded with %loop.body3...
+; CHECK-NOT: %loop.inner1.end
+; CHECK: %loop.body4
+; CHECK: %loop.inner2.begin
+; The loop.inner2.end block is folded
+; CHECK: %bail
+
+entry:
+ br label %loop.header
+
+loop.header:
+ %comp0 = icmp eq i32* undef, null
+ br i1 %comp0, label %bail, label %loop.body1
+
+loop.body1:
+ %val0 = load i32** undef, align 4
+ br i1 undef, label %loop.body2, label %loop.inner1.begin
+
+loop.body2:
+ br i1 undef, label %loop.body4, label %loop.body3
+
+loop.body3:
+ %ptr1 = getelementptr inbounds i32* %val0, i32 0
+ %castptr1 = bitcast i32* %ptr1 to i32**
+ %val1 = load i32** %castptr1, align 4
+ br label %loop.inner1.begin
+
+loop.inner1.begin:
+ %valphi = phi i32* [ %val2, %loop.inner1.end ], [ %val1, %loop.body3 ], [ %val0, %loop.body1 ]
+ %castval = bitcast i32* %valphi to i32*
+ %comp1 = icmp eq i32 undef, 48
+ br i1 %comp1, label %loop.inner1.end, label %loop.body4
+
+loop.inner1.end:
+ %ptr2 = getelementptr inbounds i32* %valphi, i32 0
+ %castptr2 = bitcast i32* %ptr2 to i32**
+ %val2 = load i32** %castptr2, align 4
+ br label %loop.inner1.begin
+
+loop.body4.dead:
+ br label %loop.body4
+
+loop.body4:
+ %comp2 = icmp ult i32 undef, 3
+ br i1 %comp2, label %loop.inner2.begin, label %loop.end
+
+loop.inner2.begin:
+ br i1 false, label %loop.end, label %loop.inner2.end
+
+loop.inner2.end:
+ %comp3 = icmp eq i32 undef, 1769472
+ br i1 %comp3, label %loop.end, label %loop.inner2.begin
+
+loop.end:
+ br label %loop.header
+
+bail:
+ unreachable
+}
+
+define i32 @problematic_switch() {
+; This function's CFG caused overlow in the machine branch probability
+; calculation, triggering asserts. Make sure we don't crash on it.
+; CHECK: problematic_switch
+
+entry:
+ switch i32 undef, label %exit [
+ i32 879, label %bogus
+ i32 877, label %step
+ i32 876, label %step
+ i32 875, label %step
+ i32 874, label %step
+ i32 873, label %step
+ i32 872, label %step
+ i32 868, label %step
+ i32 867, label %step
+ i32 866, label %step
+ i32 861, label %step
+ i32 860, label %step
+ i32 856, label %step
+ i32 855, label %step
+ i32 854, label %step
+ i32 831, label %step
+ i32 830, label %step
+ i32 829, label %step
+ i32 828, label %step
+ i32 815, label %step
+ i32 814, label %step
+ i32 811, label %step
+ i32 806, label %step
+ i32 805, label %step
+ i32 804, label %step
+ i32 803, label %step
+ i32 802, label %step
+ i32 801, label %step
+ i32 800, label %step
+ i32 799, label %step
+ i32 798, label %step
+ i32 797, label %step
+ i32 796, label %step
+ i32 795, label %step
+ ]
+bogus:
+ unreachable
+step:
+ br label %exit
+exit:
+ %merge = phi i32 [ 3, %step ], [ 6, %entry ]
+ ret i32 %merge
+}
+
+define void @fpcmp_unanalyzable_branch(i1 %cond) {
+; This function's CFG contains an unanalyzable branch that is likely to be
+; split due to having a different high-probability predecessor.
+; CHECK: fpcmp_unanalyzable_branch
+; CHECK: %entry
+; CHECK: %exit
+; CHECK-NOT: %if.then
+; CHECK-NOT: %if.end
+; CHECK-NOT: jne
+; CHECK-NOT: jnp
+; CHECK: jne
+; CHECK-NEXT: jnp
+; CHECK-NEXT: %if.then
+
+entry:
+; Note that this branch must be strongly biased toward
+; 'entry.if.then_crit_edge' to ensure that we would try to form a chain for
+; 'entry' -> 'entry.if.then_crit_edge' -> 'if.then'. It is the last edge in that
+; chain which would violate the unanalyzable branch in 'exit', but we won't even
+; try this trick unless 'if.then' is believed to almost always be reached from
+; 'entry.if.then_crit_edge'.
+ br i1 %cond, label %entry.if.then_crit_edge, label %lor.lhs.false, !prof !1
+
+entry.if.then_crit_edge:
+ %.pre14 = load i8* undef, align 1, !tbaa !0
+ br label %if.then
+
+lor.lhs.false:
+ br i1 undef, label %if.end, label %exit
+
+exit:
+ %cmp.i = fcmp une double 0.000000e+00, undef
+ br i1 %cmp.i, label %if.then, label %if.end
+
+if.then:
+ %0 = phi i8 [ %.pre14, %entry.if.then_crit_edge ], [ undef, %exit ]
+ %1 = and i8 %0, 1
+ store i8 %1, i8* undef, align 4, !tbaa !0
+ br label %if.end
+
+if.end:
+ ret void
+}
+
+!1 = metadata !{metadata !"branch_weights", i32 1000, i32 1}
+
+declare i32 @f()
+declare i32 @g()
+declare i32 @h(i32 %x)
+
+define i32 @test_global_cfg_break_profitability() {
+; Check that our metrics for the profitability of a CFG break are global rather
+; than local. A successor may be very hot, but if the current block isn't, it
+; doesn't matter. Within this test the 'then' block is slightly warmer than the
+; 'else' block, but not nearly enough to merit merging it with the exit block
+; even though the probability of 'then' branching to the 'exit' block is very
+; high.
+; CHECK: test_global_cfg_break_profitability
+; CHECK: calll {{_?}}f
+; CHECK: calll {{_?}}g
+; CHECK: calll {{_?}}h
+; CHECK: ret
+
+entry:
+ br i1 undef, label %then, label %else, !prof !2
+
+then:
+ %then.result = call i32 @f()
+ br label %exit
+
+else:
+ %else.result = call i32 @g()
+ br label %exit
+
+exit:
+ %result = phi i32 [ %then.result, %then ], [ %else.result, %else ]
+ %result2 = call i32 @h(i32 %result)
+ ret i32 %result
+}
+
+!2 = metadata !{metadata !"branch_weights", i32 3, i32 1}
+
+declare i32 @__gxx_personality_v0(...)
+
+define void @test_eh_lpad_successor() {
+; Some times the landing pad ends up as the first successor of an invoke block.
+; When this happens, a strange result used to fall out of updateTerminators: we
+; didn't correctly locate the fallthrough successor, assuming blindly that the
+; first one was the fallthrough successor. As a result, we would add an
+; erroneous jump to the landing pad thinking *that* was the default successor.
+; CHECK: test_eh_lpad_successor
+; CHECK: %entry
+; CHECK-NOT: jmp
+; CHECK: %loop
+
+entry:
+ invoke i32 @f() to label %preheader unwind label %lpad
+
+preheader:
+ br label %loop
+
+lpad:
+ %lpad.val = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ resume { i8*, i32 } %lpad.val
+
+loop:
+ br label %loop
+}
+
+declare void @fake_throw() noreturn
+
+define void @test_eh_throw() {
+; For blocks containing a 'throw' (or similar functionality), we have
+; a no-return invoke. In this case, only EH successors will exist, and
+; fallthrough simply won't occur. Make sure we don't crash trying to update
+; terminators for such constructs.
+;
+; CHECK: test_eh_throw
+; CHECK: %entry
+; CHECK: %cleanup
+
+entry:
+ invoke void @fake_throw() to label %continue unwind label %cleanup
+
+continue:
+ unreachable
+
+cleanup:
+ %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ unreachable
+}
+
+define void @test_unnatural_cfg_backwards_inner_loop() {
+; Test that when we encounter an unnatural CFG structure after having formed
+; a chain for an inner loop which happened to be laid out backwards we don't
+; attempt to merge onto the wrong end of the inner loop just because we find it
+; first. This was reduced from a crasher in GCC's single source.
+;
+; CHECK: test_unnatural_cfg_backwards_inner_loop
+; CHECK: %entry
+; CHECK: %body
+; CHECK: %loop1
+; CHECK: %loop2b
+; CHECK: %loop2a
+
+entry:
+ br i1 undef, label %loop2a, label %body
+
+body:
+ br label %loop2a
+
+loop1:
+ %next.load = load i32** undef
+ br i1 %comp.a, label %loop2a, label %loop2b
+
+loop2a:
+ %var = phi i32* [ null, %entry ], [ null, %body ], [ %next.phi, %loop1 ]
+ %next.var = phi i32* [ null, %entry ], [ undef, %body ], [ %next.load, %loop1 ]
+ %comp.a = icmp eq i32* %var, null
+ br label %loop3
+
+loop2b:
+ %gep = getelementptr inbounds i32* %var.phi, i32 0
+ %next.ptr = bitcast i32* %gep to i32**
+ store i32* %next.phi, i32** %next.ptr
+ br label %loop3
+
+loop3:
+ %var.phi = phi i32* [ %next.phi, %loop2b ], [ %var, %loop2a ]
+ %next.phi = phi i32* [ %next.load, %loop2b ], [ %next.var, %loop2a ]
+ br label %loop1
+}
+
+define void @unanalyzable_branch_to_loop_header() {
+; Ensure that we can handle unanalyzable branches into loop headers. We
+; pre-form chains for unanalyzable branches, and will find the tail end of that
+; at the start of the loop. This function uses floating point comparison
+; fallthrough because that happens to always produce unanalyzable branches on
+; x86.
+;
+; CHECK: unanalyzable_branch_to_loop_header
+; CHECK: %entry
+; CHECK: %loop
+; CHECK: %exit
+
+entry:
+ %cmp = fcmp une double 0.000000e+00, undef
+ br i1 %cmp, label %loop, label %exit
+
+loop:
+ %cond = icmp eq i8 undef, 42
+ br i1 %cond, label %exit, label %loop
+
+exit:
+ ret void
+}
+
projects / oota-llvm.git / blobdiff