; 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-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 ; CHECK: %then3 ; CHECK: %then4 ; CHECK: %then5 entry: %gep1 = getelementptr i32, i32* %a, i32 1 %val1 = load i32, i32* %gep1 %cond1 = icmp ugt i32 %val1, 1 br i1 %cond1, label %then1, label %else1, !prof !0 then1: call void @error(i32 %i, i32 1, i32 %b) br label %else1 else1: %gep2 = getelementptr i32, i32* %a, i32 2 %val2 = load i32, i32* %gep2 %cond2 = icmp ugt i32 %val2, 2 br i1 %cond2, label %then2, label %else2, !prof !0 then2: call void @error(i32 %i, i32 1, i32 %b) br label %else2 else2: %gep3 = getelementptr i32, i32* %a, i32 3 %val3 = load i32, i32* %gep3 %cond3 = icmp ugt i32 %val3, 3 br i1 %cond3, label %then3, label %else3, !prof !0 then3: call void @error(i32 %i, i32 1, i32 %b) br label %else3 else3: %gep4 = getelementptr i32, i32* %a, i32 4 %val4 = load i32, i32* %gep4 %cond4 = icmp ugt i32 %val4, 4 br i1 %cond4, label %then4, label %else4, !prof !0 then4: call void @error(i32 %i, i32 1, i32 %b) br label %else4 else4: %gep5 = getelementptr i32, i32* %a, i32 3 %val5 = load i32, i32* %gep5 %cond5 = icmp ugt i32 %val5, 3 br i1 %cond5, label %then5, label %exit, !prof !0 then5: call void @error(i32 %i, i32 1, i32 %b) br label %exit exit: 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-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: %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, i32* %a, i32 %iv %0 = load i32, 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 = !{!"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-LABEL: 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, i32* %a, i32 %iv %0 = load i32, 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_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, i32* %a, i32 %iv %0 = load i32, 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, i32* %a, i32 %iv %0 = load i32, 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-LABEL: test_loop_align: ; CHECK: %entry ; CHECK: .align [[ALIGN:[0-9]+]], ; CHECK-NEXT: %body ; CHECK: %exit entry: br label %body body: %iv = phi i32 [ 0, %entry ], [ %next, %body ] %base = phi i32 [ 0, %entry ], [ %sum, %body ] %arrayidx = getelementptr inbounds i32, i32* %a, i32 %iv %0 = load i32, 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 %body exit: ret i32 %sum } define i32 @test_nested_loop_align(i32 %i, i32* %a, i32* %b) { ; Check that we provide nested loop body alignment. ; CHECK-LABEL: test_nested_loop_align: ; CHECK: %entry ; CHECK: .align [[ALIGN]], ; CHECK-NEXT: %loop.body.1 ; CHECK: .align [[ALIGN]], ; CHECK-NEXT: %inner.loop.body ; CHECK-NOT: .align ; CHECK: %exit entry: br label %loop.body.1 loop.body.1: %iv = phi i32 [ 0, %entry ], [ %next, %loop.body.2 ] %arrayidx = getelementptr inbounds i32, i32* %a, i32 %iv %bidx = load i32, i32* %arrayidx br label %inner.loop.body inner.loop.body: %inner.iv = phi i32 [ 0, %loop.body.1 ], [ %inner.next, %inner.loop.body ] %base = phi i32 [ 0, %loop.body.1 ], [ %sum, %inner.loop.body ] %scaled_idx = mul i32 %bidx, %iv %inner.arrayidx = getelementptr inbounds i32, i32* %b, i32 %scaled_idx %0 = load i32, i32* %inner.arrayidx %sum = add nsw i32 %0, %base %inner.next = add i32 %iv, 1 %inner.exitcond = icmp eq i32 %inner.next, %i br i1 %inner.exitcond, label %loop.body.2, label %inner.loop.body loop.body.2: %next = add i32 %iv, 1 %exitcond = icmp eq i32 %next, %i br i1 %exitcond, label %exit, label %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*, 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, 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*, 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*, 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, i32* %val0, i32 0 %castptr1 = bitcast i32* %ptr1 to i32** %val1 = load i32*, 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, i32* %valphi, i32 0 %castptr2 = bitcast i32* %ptr2 to i32** %val2 = load i32*, 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, 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 = !{!"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 = !{!"branch_weights", i32 3, i32 1} declare i32 @__gxx_personality_v0(...) define void @test_eh_lpad_successor() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { ; 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 } cleanup resume { i8*, i32 } %lpad.val loop: br label %loop } declare void @fake_throw() noreturn define void @test_eh_throw() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { ; 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 } 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*, 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, 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, float* undef %cmp0 = fcmp une float %val0, undef br i1 %cmp0, label %1, label %0 %val1 = load volatile float, float* undef %cmp1 = fcmp une float %val1, undef br i1 %cmp1, label %2, label %1 %val2 = load volatile float, float* undef %cmp2 = fcmp une float %val2, undef br i1 %cmp2, label %3, label %2 %val3 = load volatile float, float* undef %cmp3 = fcmp une float %val3, undef br i1 %cmp3, label %4, label %3 %val4 = load volatile float, float* undef %cmp4 = fcmp une float %val4, undef br i1 %cmp4, label %5, label %4 %val5 = load volatile float, float* undef %cmp5 = fcmp une float %val5, undef br i1 %cmp5, label %6, label %5 %val6 = load volatile float, float* undef %cmp6 = fcmp une float %val6, undef br i1 %cmp6, label %7, label %6 %val7 = load volatile float, float* undef %cmp7 = fcmp une float %val7, undef br i1 %cmp7, label %8, label %7 %val8 = load volatile float, float* undef %cmp8 = fcmp une float %val8, undef br i1 %cmp8, label %9, label %8 %val9 = load volatile float, float* undef %cmp9 = fcmp une float %val9, undef br i1 %cmp9, label %10, label %9 %val10 = load volatile float, float* undef %cmp10 = fcmp une float %val10, undef br i1 %cmp10, label %11, label %10 %val11 = load volatile float, float* undef %cmp11 = fcmp une float %val11, undef br i1 %cmp11, label %12, label %11 %val12 = load volatile float, float* undef %cmp12 = fcmp une float %val12, undef br i1 %cmp12, label %13, label %12 %val13 = load volatile float, float* undef %cmp13 = fcmp une float %val13, undef br i1 %cmp13, label %14, label %13 %val14 = load volatile float, float* undef %cmp14 = fcmp une float %val14, undef br i1 %cmp14, label %15, label %14 %val15 = load volatile float, float* undef %cmp15 = fcmp une float %val15, undef br i1 %cmp15, label %16, label %15 %val16 = load volatile float, float* undef %cmp16 = fcmp une float %val16, undef br i1 %cmp16, label %17, label %16 %val17 = load volatile float, float* undef %cmp17 = fcmp une float %val17, undef br i1 %cmp17, label %18, label %17 %val18 = load volatile float, float* undef %cmp18 = fcmp une float %val18, undef br i1 %cmp18, label %19, label %18 %val19 = load volatile float, float* undef %cmp19 = fcmp une float %val19, undef br i1 %cmp19, label %20, label %19 %val20 = load volatile float, float* undef %cmp20 = fcmp une float %val20, undef br i1 %cmp20, label %21, label %20 %val21 = load volatile float, float* undef %cmp21 = fcmp une float %val21, undef br i1 %cmp21, label %22, label %21 %val22 = load volatile float, float* undef %cmp22 = fcmp une float %val22, undef br i1 %cmp22, label %23, label %22 %val23 = load volatile float, float* undef %cmp23 = fcmp une float %val23, undef br i1 %cmp23, label %24, label %23 %val24 = load volatile float, float* undef %cmp24 = fcmp une float %val24, undef br i1 %cmp24, label %25, label %24 %val25 = load volatile float, float* undef %cmp25 = fcmp une float %val25, undef br i1 %cmp25, label %26, label %25 %val26 = load volatile float, float* undef %cmp26 = fcmp une float %val26, undef br i1 %cmp26, label %27, label %26 %val27 = load volatile float, float* undef %cmp27 = fcmp une float %val27, undef br i1 %cmp27, label %28, label %27 %val28 = load volatile float, float* undef %cmp28 = fcmp une float %val28, undef br i1 %cmp28, label %29, label %28 %val29 = load volatile float, float* undef %cmp29 = fcmp une float %val29, undef br i1 %cmp29, label %30, label %29 %val30 = load volatile float, float* undef %cmp30 = fcmp une float %val30, undef br i1 %cmp30, label %31, label %30 %val31 = load volatile float, float* undef %cmp31 = fcmp une float %val31, undef br i1 %cmp31, label %32, label %31 %val32 = load volatile float, float* undef %cmp32 = fcmp une float %val32, undef br i1 %cmp32, label %33, label %32 %val33 = load volatile float, float* undef %cmp33 = fcmp une float %val33, undef br i1 %cmp33, label %34, label %33 %val34 = load volatile float, float* undef %cmp34 = fcmp une float %val34, undef br i1 %cmp34, label %35, label %34 %val35 = load volatile float, float* undef %cmp35 = fcmp une float %val35, undef br i1 %cmp35, label %36, label %35 %val36 = load volatile float, float* undef %cmp36 = fcmp une float %val36, undef br i1 %cmp36, label %37, label %36 %val37 = load volatile float, float* undef %cmp37 = fcmp une float %val37, undef br i1 %cmp37, label %38, label %37 %val38 = load volatile float, float* undef %cmp38 = fcmp une float %val38, undef br i1 %cmp38, label %39, label %38 %val39 = load volatile float, float* undef %cmp39 = fcmp une float %val39, undef br i1 %cmp39, label %40, label %39 %val40 = load volatile float, float* undef %cmp40 = fcmp une float %val40, undef br i1 %cmp40, label %41, label %40 %val41 = load volatile float, float* undef %cmp41 = fcmp une float %val41, undef br i1 %cmp41, label %42, label %41 %val42 = load volatile float, float* undef %cmp42 = fcmp une float %val42, undef br i1 %cmp42, label %43, label %42 %val43 = load volatile float, float* undef %cmp43 = fcmp une float %val43, undef br i1 %cmp43, label %44, label %43 %val44 = load volatile float, float* undef %cmp44 = fcmp une float %val44, undef br i1 %cmp44, label %45, label %44 %val45 = load volatile float, float* undef %cmp45 = fcmp une float %val45, undef br i1 %cmp45, label %46, label %45 %val46 = load volatile float, float* undef %cmp46 = fcmp une float %val46, undef br i1 %cmp46, label %47, label %46 %val47 = load volatile float, float* undef %cmp47 = fcmp une float %val47, undef br i1 %cmp47, label %48, label %47 %val48 = load volatile float, float* undef %cmp48 = fcmp une float %val48, undef br i1 %cmp48, label %49, label %48 %val49 = load volatile float, float* undef %cmp49 = fcmp une float %val49, undef br i1 %cmp49, label %50, label %49 %val50 = load volatile float, float* undef %cmp50 = fcmp une float %val50, undef br i1 %cmp50, label %51, label %50 %val51 = load volatile float, float* undef %cmp51 = fcmp une float %val51, undef br i1 %cmp51, label %52, label %51 %val52 = load volatile float, float* undef %cmp52 = fcmp une float %val52, undef br i1 %cmp52, label %53, label %52 %val53 = load volatile float, float* undef %cmp53 = fcmp une float %val53, undef br i1 %cmp53, label %54, label %53 %val54 = load volatile float, float* undef %cmp54 = fcmp une float %val54, undef br i1 %cmp54, label %55, label %54 %val55 = load volatile float, float* undef %cmp55 = fcmp une float %val55, undef br i1 %cmp55, label %56, label %55 %val56 = load volatile float, float* undef %cmp56 = fcmp une float %val56, undef br i1 %cmp56, label %57, label %56 %val57 = load volatile float, float* undef %cmp57 = fcmp une float %val57, undef br i1 %cmp57, label %58, label %57 %val58 = load volatile float, float* undef %cmp58 = fcmp une float %val58, undef br i1 %cmp58, label %59, label %58 %val59 = load volatile float, float* undef %cmp59 = fcmp une float %val59, undef br i1 %cmp59, label %60, label %59 %val60 = load volatile float, float* undef %cmp60 = fcmp une float %val60, undef br i1 %cmp60, label %61, label %60 %val61 = load volatile float, float* undef %cmp61 = fcmp une float %val61, undef br i1 %cmp61, label %62, label %61 %val62 = load volatile float, float* undef %cmp62 = fcmp une float %val62, undef br i1 %cmp62, label %63, label %62 %val63 = load volatile float, float* undef %cmp63 = fcmp une float %val63, undef br i1 %cmp63, label %64, label %63 %val64 = load volatile float, 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, 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, double* %ra, i64 %idxprom %0 = load double, double* %arrayidx, align 8 br label %if.end10 if.else: %idxprom1 = sext i32 %ir.0 to i64 %arrayidx2 = getelementptr inbounds double, double* %ra, i64 %idxprom1 %1 = load double, double* %arrayidx2, align 8 %2 = load double, 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, double* %ra, i64 %idxprom13 %3 = load double, double* %arrayidx14, align 8 %add15 = add nsw i32 %j.0, 1 %idxprom16 = sext i32 %add15 to i64 %arrayidx17 = getelementptr inbounds double, double* %ra, i64 %idxprom16 %4 = load double, 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, double* %ra, i64 %idxprom21 %5 = load double, 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, 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, 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, i32* %a, i32 1 %val1 = load i32, 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, i32* %a, i32 2 %val2 = load i32, i32* %gep2 br label %exit exit: %ret = phi i32 [ %val1, %then ], [ %val2, %else ] ret i32 %ret }