-; RUN: llc -march=x86 -enable-block-placement < %s | FileCheck %s
+; RUN: llc -mtriple=i686-linux -pre-RA-sched=source < %s | FileCheck %s
declare void @error(i32 %i, i32 %a, i32 %b)
define i32 @test_ifchains(i32 %i, i32* %a, i32 %b) {
; Test a chain of ifs, where the block guarded by the if is error handling code
; that is not expected to run.
-; CHECK: test_ifchains:
+; CHECK-LABEL: test_ifchains:
; CHECK: %entry
+; CHECK-NOT: .align
; CHECK: %else1
+; CHECK-NOT: .align
; CHECK: %else2
+; CHECK-NOT: .align
; CHECK: %else3
+; CHECK-NOT: .align
; CHECK: %else4
+; CHECK-NOT: .align
; CHECK: %exit
; CHECK: %then1
; CHECK: %then2
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-LABEL: test_loop_cold_blocks:
; CHECK: %entry
+; CHECK-NOT: .align
+; CHECK: %unlikely1
+; CHECK-NOT: .align
+; CHECK: %unlikely2
+; CHECK: .align
; CHECK: %body1
; CHECK: %body2
; CHECK: %body3
-; CHECK: %unlikely1
-; CHECK: %unlikely2
; CHECK: %exit
entry:
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-LABEL: test_loop_early_exits:
; CHECK: %entry
; CHECK: %body1
; CHECK: %body2
ret i32 %sum
}
+define i32 @test_loop_rotate(i32 %i, i32* %a) {
+; Check that we rotate conditional exits from the loop to the bottom of the
+; loop, eliminating unconditional branches to the top.
+; CHECK-LABEL: test_loop_rotate:
+; CHECK: %entry
+; CHECK: %body1
+; CHECK: %body0
+; CHECK: %exit
+
+entry:
+ br label %body0
+
+body0:
+ %iv = phi i32 [ 0, %entry ], [ %next, %body1 ]
+ %base = phi i32 [ 0, %entry ], [ %sum, %body1 ]
+ %next = add i32 %iv, 1
+ %exitcond = icmp eq i32 %next, %i
+ br i1 %exitcond, label %exit, label %body1
+
+body1:
+ %arrayidx = getelementptr inbounds i32* %a, i32 %iv
+ %0 = load i32* %arrayidx
+ %sum = add nsw i32 %0, %base
+ %bailcond1 = icmp eq i32 %sum, 42
+ br label %body0
+
+exit:
+ ret i32 %base
+}
+
+define i32 @test_no_loop_rotate(i32 %i, i32* %a) {
+; Check that we don't try to rotate a loop which is already laid out with
+; fallthrough opportunities into the top and out of the bottom.
+; CHECK-LABEL: test_no_loop_rotate:
+; CHECK: %entry
+; CHECK: %body0
+; CHECK: %body1
+; CHECK: %exit
+
+entry:
+ br label %body0
+
+body0:
+ %iv = phi i32 [ 0, %entry ], [ %next, %body1 ]
+ %base = phi i32 [ 0, %entry ], [ %sum, %body1 ]
+ %arrayidx = getelementptr inbounds i32* %a, i32 %iv
+ %0 = load i32* %arrayidx
+ %sum = add nsw i32 %0, %base
+ %bailcond1 = icmp eq i32 %sum, 42
+ br i1 %bailcond1, label %exit, label %body1
+
+body1:
+ %next = add i32 %iv, 1
+ %exitcond = icmp eq i32 %next, %i
+ br i1 %exitcond, label %exit, label %body0
+
+exit:
+ ret i32 %base
+}
+
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-LABEL: test_loop_align:
; CHECK: %entry
; CHECK: .align [[ALIGN:[0-9]+]],
; CHECK-NEXT: %body
define i32 @test_nested_loop_align(i32 %i, i32* %a, i32* %b) {
; Check that we provide nested loop body alignment.
-; CHECK: test_nested_loop_align:
+; CHECK-LABEL: test_nested_loop_align:
; CHECK: %entry
; CHECK: .align [[ALIGN]],
; CHECK-NEXT: %loop.body.1
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.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: %loop.header
+; 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
+ 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
+ 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:# BB#[0-9]+]]:
+; CHECK: %loop2b
+; CHECK: %loop1
+; 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
+}
+
+define void @unanalyzable_branch_to_best_succ(i1 %cond) {
+; Ensure that we can handle unanalyzable branches where the destination block
+; gets selected as the optimal successor to merge.
+;
+; CHECK: unanalyzable_branch_to_best_succ
+; CHECK: %entry
+; CHECK: %foo
+; CHECK: %bar
+; CHECK: %exit
+
+entry:
+ ; Bias this branch toward bar to ensure we form that chain.
+ br i1 %cond, label %bar, label %foo, !prof !1
+
+foo:
+ %cmp = fcmp une double 0.000000e+00, undef
+ br i1 %cmp, label %bar, label %exit
+
+bar:
+ call i32 @f()
+ br label %exit
+
+exit:
+ ret void
+}
+
+define void @unanalyzable_branch_to_free_block(float %x) {
+; Ensure that we can handle unanalyzable branches where the destination block
+; gets selected as the best free block in the CFG.
+;
+; CHECK: unanalyzable_branch_to_free_block
+; CHECK: %entry
+; CHECK: %a
+; CHECK: %b
+; CHECK: %c
+; CHECK: %exit
+
+entry:
+ br i1 undef, label %a, label %b
+
+a:
+ call i32 @f()
+ br label %c
+
+b:
+ %cmp = fcmp une float %x, undef
+ br i1 %cmp, label %c, label %exit
+
+c:
+ call i32 @g()
+ br label %exit
+
+exit:
+ ret void
+}
+
+define void @many_unanalyzable_branches() {
+; Ensure that we don't crash as we're building up many unanalyzable branches,
+; blocks, and loops.
+;
+; CHECK: many_unanalyzable_branches
+; CHECK: %entry
+; CHECK: %exit
+
+entry:
+ br label %0
+
+ %val0 = load volatile float* undef
+ %cmp0 = fcmp une float %val0, undef
+ br i1 %cmp0, label %1, label %0
+ %val1 = load volatile float* undef
+ %cmp1 = fcmp une float %val1, undef
+ br i1 %cmp1, label %2, label %1
+ %val2 = load volatile float* undef
+ %cmp2 = fcmp une float %val2, undef
+ br i1 %cmp2, label %3, label %2
+ %val3 = load volatile float* undef
+ %cmp3 = fcmp une float %val3, undef
+ br i1 %cmp3, label %4, label %3
+ %val4 = load volatile float* undef
+ %cmp4 = fcmp une float %val4, undef
+ br i1 %cmp4, label %5, label %4
+ %val5 = load volatile float* undef
+ %cmp5 = fcmp une float %val5, undef
+ br i1 %cmp5, label %6, label %5
+ %val6 = load volatile float* undef
+ %cmp6 = fcmp une float %val6, undef
+ br i1 %cmp6, label %7, label %6
+ %val7 = load volatile float* undef
+ %cmp7 = fcmp une float %val7, undef
+ br i1 %cmp7, label %8, label %7
+ %val8 = load volatile float* undef
+ %cmp8 = fcmp une float %val8, undef
+ br i1 %cmp8, label %9, label %8
+ %val9 = load volatile float* undef
+ %cmp9 = fcmp une float %val9, undef
+ br i1 %cmp9, label %10, label %9
+ %val10 = load volatile float* undef
+ %cmp10 = fcmp une float %val10, undef
+ br i1 %cmp10, label %11, label %10
+ %val11 = load volatile float* undef
+ %cmp11 = fcmp une float %val11, undef
+ br i1 %cmp11, label %12, label %11
+ %val12 = load volatile float* undef
+ %cmp12 = fcmp une float %val12, undef
+ br i1 %cmp12, label %13, label %12
+ %val13 = load volatile float* undef
+ %cmp13 = fcmp une float %val13, undef
+ br i1 %cmp13, label %14, label %13
+ %val14 = load volatile float* undef
+ %cmp14 = fcmp une float %val14, undef
+ br i1 %cmp14, label %15, label %14
+ %val15 = load volatile float* undef
+ %cmp15 = fcmp une float %val15, undef
+ br i1 %cmp15, label %16, label %15
+ %val16 = load volatile float* undef
+ %cmp16 = fcmp une float %val16, undef
+ br i1 %cmp16, label %17, label %16
+ %val17 = load volatile float* undef
+ %cmp17 = fcmp une float %val17, undef
+ br i1 %cmp17, label %18, label %17
+ %val18 = load volatile float* undef
+ %cmp18 = fcmp une float %val18, undef
+ br i1 %cmp18, label %19, label %18
+ %val19 = load volatile float* undef
+ %cmp19 = fcmp une float %val19, undef
+ br i1 %cmp19, label %20, label %19
+ %val20 = load volatile float* undef
+ %cmp20 = fcmp une float %val20, undef
+ br i1 %cmp20, label %21, label %20
+ %val21 = load volatile float* undef
+ %cmp21 = fcmp une float %val21, undef
+ br i1 %cmp21, label %22, label %21
+ %val22 = load volatile float* undef
+ %cmp22 = fcmp une float %val22, undef
+ br i1 %cmp22, label %23, label %22
+ %val23 = load volatile float* undef
+ %cmp23 = fcmp une float %val23, undef
+ br i1 %cmp23, label %24, label %23
+ %val24 = load volatile float* undef
+ %cmp24 = fcmp une float %val24, undef
+ br i1 %cmp24, label %25, label %24
+ %val25 = load volatile float* undef
+ %cmp25 = fcmp une float %val25, undef
+ br i1 %cmp25, label %26, label %25
+ %val26 = load volatile float* undef
+ %cmp26 = fcmp une float %val26, undef
+ br i1 %cmp26, label %27, label %26
+ %val27 = load volatile float* undef
+ %cmp27 = fcmp une float %val27, undef
+ br i1 %cmp27, label %28, label %27
+ %val28 = load volatile float* undef
+ %cmp28 = fcmp une float %val28, undef
+ br i1 %cmp28, label %29, label %28
+ %val29 = load volatile float* undef
+ %cmp29 = fcmp une float %val29, undef
+ br i1 %cmp29, label %30, label %29
+ %val30 = load volatile float* undef
+ %cmp30 = fcmp une float %val30, undef
+ br i1 %cmp30, label %31, label %30
+ %val31 = load volatile float* undef
+ %cmp31 = fcmp une float %val31, undef
+ br i1 %cmp31, label %32, label %31
+ %val32 = load volatile float* undef
+ %cmp32 = fcmp une float %val32, undef
+ br i1 %cmp32, label %33, label %32
+ %val33 = load volatile float* undef
+ %cmp33 = fcmp une float %val33, undef
+ br i1 %cmp33, label %34, label %33
+ %val34 = load volatile float* undef
+ %cmp34 = fcmp une float %val34, undef
+ br i1 %cmp34, label %35, label %34
+ %val35 = load volatile float* undef
+ %cmp35 = fcmp une float %val35, undef
+ br i1 %cmp35, label %36, label %35
+ %val36 = load volatile float* undef
+ %cmp36 = fcmp une float %val36, undef
+ br i1 %cmp36, label %37, label %36
+ %val37 = load volatile float* undef
+ %cmp37 = fcmp une float %val37, undef
+ br i1 %cmp37, label %38, label %37
+ %val38 = load volatile float* undef
+ %cmp38 = fcmp une float %val38, undef
+ br i1 %cmp38, label %39, label %38
+ %val39 = load volatile float* undef
+ %cmp39 = fcmp une float %val39, undef
+ br i1 %cmp39, label %40, label %39
+ %val40 = load volatile float* undef
+ %cmp40 = fcmp une float %val40, undef
+ br i1 %cmp40, label %41, label %40
+ %val41 = load volatile float* undef
+ %cmp41 = fcmp une float %val41, undef
+ br i1 %cmp41, label %42, label %41
+ %val42 = load volatile float* undef
+ %cmp42 = fcmp une float %val42, undef
+ br i1 %cmp42, label %43, label %42
+ %val43 = load volatile float* undef
+ %cmp43 = fcmp une float %val43, undef
+ br i1 %cmp43, label %44, label %43
+ %val44 = load volatile float* undef
+ %cmp44 = fcmp une float %val44, undef
+ br i1 %cmp44, label %45, label %44
+ %val45 = load volatile float* undef
+ %cmp45 = fcmp une float %val45, undef
+ br i1 %cmp45, label %46, label %45
+ %val46 = load volatile float* undef
+ %cmp46 = fcmp une float %val46, undef
+ br i1 %cmp46, label %47, label %46
+ %val47 = load volatile float* undef
+ %cmp47 = fcmp une float %val47, undef
+ br i1 %cmp47, label %48, label %47
+ %val48 = load volatile float* undef
+ %cmp48 = fcmp une float %val48, undef
+ br i1 %cmp48, label %49, label %48
+ %val49 = load volatile float* undef
+ %cmp49 = fcmp une float %val49, undef
+ br i1 %cmp49, label %50, label %49
+ %val50 = load volatile float* undef
+ %cmp50 = fcmp une float %val50, undef
+ br i1 %cmp50, label %51, label %50
+ %val51 = load volatile float* undef
+ %cmp51 = fcmp une float %val51, undef
+ br i1 %cmp51, label %52, label %51
+ %val52 = load volatile float* undef
+ %cmp52 = fcmp une float %val52, undef
+ br i1 %cmp52, label %53, label %52
+ %val53 = load volatile float* undef
+ %cmp53 = fcmp une float %val53, undef
+ br i1 %cmp53, label %54, label %53
+ %val54 = load volatile float* undef
+ %cmp54 = fcmp une float %val54, undef
+ br i1 %cmp54, label %55, label %54
+ %val55 = load volatile float* undef
+ %cmp55 = fcmp une float %val55, undef
+ br i1 %cmp55, label %56, label %55
+ %val56 = load volatile float* undef
+ %cmp56 = fcmp une float %val56, undef
+ br i1 %cmp56, label %57, label %56
+ %val57 = load volatile float* undef
+ %cmp57 = fcmp une float %val57, undef
+ br i1 %cmp57, label %58, label %57
+ %val58 = load volatile float* undef
+ %cmp58 = fcmp une float %val58, undef
+ br i1 %cmp58, label %59, label %58
+ %val59 = load volatile float* undef
+ %cmp59 = fcmp une float %val59, undef
+ br i1 %cmp59, label %60, label %59
+ %val60 = load volatile float* undef
+ %cmp60 = fcmp une float %val60, undef
+ br i1 %cmp60, label %61, label %60
+ %val61 = load volatile float* undef
+ %cmp61 = fcmp une float %val61, undef
+ br i1 %cmp61, label %62, label %61
+ %val62 = load volatile float* undef
+ %cmp62 = fcmp une float %val62, undef
+ br i1 %cmp62, label %63, label %62
+ %val63 = load volatile float* undef
+ %cmp63 = fcmp une float %val63, undef
+ br i1 %cmp63, label %64, label %63
+ %val64 = load volatile float* undef
+ %cmp64 = fcmp une float %val64, undef
+ br i1 %cmp64, label %65, label %64
+
+ br label %exit
+exit:
+ ret void
+}
+
+define void @benchmark_heapsort(i32 %n, double* nocapture %ra) {
+; This test case comes from the heapsort benchmark, and exemplifies several
+; important aspects to block placement in the presence of loops:
+; 1) Loop rotation needs to *ensure* that the desired exiting edge can be
+; a fallthrough.
+; 2) The exiting edge from the loop which is rotated to be laid out at the
+; bottom of the loop needs to be exiting into the nearest enclosing loop (to
+; which there is an exit). Otherwise, we force that enclosing loop into
+; strange layouts that are siginificantly less efficient, often times maing
+; it discontiguous.
+;
+; CHECK: @benchmark_heapsort
+; CHECK: %entry
+; First rotated loop top.
+; CHECK: .align
+; CHECK: %while.end
+; CHECK: %for.cond
+; CHECK: %if.then
+; CHECK: %if.else
+; CHECK: %if.end10
+; Second rotated loop top
+; CHECK: .align
+; CHECK: %if.then24
+; CHECK: %while.cond.outer
+; Third rotated loop top
+; CHECK: .align
+; CHECK: %while.cond
+; CHECK: %while.body
+; CHECK: %land.lhs.true
+; CHECK: %if.then19
+; CHECK: %if.end20
+; CHECK: %if.then8
+; CHECK: ret
+
+entry:
+ %shr = ashr i32 %n, 1
+ %add = add nsw i32 %shr, 1
+ %arrayidx3 = getelementptr inbounds double* %ra, i64 1
+ br label %for.cond
+
+for.cond:
+ %ir.0 = phi i32 [ %n, %entry ], [ %ir.1, %while.end ]
+ %l.0 = phi i32 [ %add, %entry ], [ %l.1, %while.end ]
+ %cmp = icmp sgt i32 %l.0, 1
+ br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+ %dec = add nsw i32 %l.0, -1
+ %idxprom = sext i32 %dec to i64
+ %arrayidx = getelementptr inbounds double* %ra, i64 %idxprom
+ %0 = load double* %arrayidx, align 8
+ br label %if.end10
+
+if.else:
+ %idxprom1 = sext i32 %ir.0 to i64
+ %arrayidx2 = getelementptr inbounds double* %ra, i64 %idxprom1
+ %1 = load double* %arrayidx2, align 8
+ %2 = load double* %arrayidx3, align 8
+ store double %2, double* %arrayidx2, align 8
+ %dec6 = add nsw i32 %ir.0, -1
+ %cmp7 = icmp eq i32 %dec6, 1
+ br i1 %cmp7, label %if.then8, label %if.end10
+
+if.then8:
+ store double %1, double* %arrayidx3, align 8
+ ret void
+
+if.end10:
+ %ir.1 = phi i32 [ %ir.0, %if.then ], [ %dec6, %if.else ]
+ %l.1 = phi i32 [ %dec, %if.then ], [ %l.0, %if.else ]
+ %rra.0 = phi double [ %0, %if.then ], [ %1, %if.else ]
+ %add31 = add nsw i32 %ir.1, 1
+ br label %while.cond.outer
+
+while.cond.outer:
+ %j.0.ph.in = phi i32 [ %l.1, %if.end10 ], [ %j.1, %if.then24 ]
+ %j.0.ph = shl i32 %j.0.ph.in, 1
+ br label %while.cond
+
+while.cond:
+ %j.0 = phi i32 [ %add31, %if.end20 ], [ %j.0.ph, %while.cond.outer ]
+ %cmp11 = icmp sgt i32 %j.0, %ir.1
+ br i1 %cmp11, label %while.end, label %while.body
+
+while.body:
+ %cmp12 = icmp slt i32 %j.0, %ir.1
+ br i1 %cmp12, label %land.lhs.true, label %if.end20
+
+land.lhs.true:
+ %idxprom13 = sext i32 %j.0 to i64
+ %arrayidx14 = getelementptr inbounds double* %ra, i64 %idxprom13
+ %3 = load double* %arrayidx14, align 8
+ %add15 = add nsw i32 %j.0, 1
+ %idxprom16 = sext i32 %add15 to i64
+ %arrayidx17 = getelementptr inbounds double* %ra, i64 %idxprom16
+ %4 = load double* %arrayidx17, align 8
+ %cmp18 = fcmp olt double %3, %4
+ br i1 %cmp18, label %if.then19, label %if.end20
+
+if.then19:
+ br label %if.end20
+
+if.end20:
+ %j.1 = phi i32 [ %add15, %if.then19 ], [ %j.0, %land.lhs.true ], [ %j.0, %while.body ]
+ %idxprom21 = sext i32 %j.1 to i64
+ %arrayidx22 = getelementptr inbounds double* %ra, i64 %idxprom21
+ %5 = load double* %arrayidx22, align 8
+ %cmp23 = fcmp olt double %rra.0, %5
+ br i1 %cmp23, label %if.then24, label %while.cond
+
+if.then24:
+ %idxprom27 = sext i32 %j.0.ph.in to i64
+ %arrayidx28 = getelementptr inbounds double* %ra, i64 %idxprom27
+ store double %5, double* %arrayidx28, align 8
+ br label %while.cond.outer
+
+while.end:
+ %idxprom33 = sext i32 %j.0.ph.in to i64
+ %arrayidx34 = getelementptr inbounds double* %ra, i64 %idxprom33
+ store double %rra.0, double* %arrayidx34, align 8
+ br label %for.cond
+}
+
+declare void @cold_function() cold
+
+define i32 @test_cold_calls(i32* %a) {
+; Test that edges to blocks post-dominated by cold calls are
+; marked as not expected to be taken. They should be laid out
+; at the bottom.
+; CHECK-LABEL: test_cold_calls:
+; CHECK: %entry
+; CHECK: %else
+; CHECK: %exit
+; CHECK: %then
+
+entry:
+ %gep1 = getelementptr i32* %a, i32 1
+ %val1 = load i32* %gep1
+ %cond1 = icmp ugt i32 %val1, 1
+ br i1 %cond1, label %then, label %else
+
+then:
+ call void @cold_function()
+ br label %exit
+
+else:
+ %gep2 = getelementptr i32* %a, i32 2
+ %val2 = load i32* %gep2
+ br label %exit
+
+exit:
+ %ret = phi i32 [ %val1, %then ], [ %val2, %else ]
+ ret i32 %ret
+}