; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; Test the basic functionality of speculating around PHI nodes based on reduced ; cost of the constant operands to the PHI nodes using the x86 cost model. ; ; REQUIRES: x86-registered-target ; RUN: opt -S -passes=spec-phis < %s | FileCheck %s target triple = "x86_64-unknown-unknown" define i32 @test_basic(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_basic( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[ARG:%.*]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[ARG]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %arg, %p ret i32 %sum } ; Check that we handle commuted operands and get the constant onto the RHS. define i32 @test_commuted(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_commuted( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[ARG:%.*]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[ARG]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %p, %arg ret i32 %sum } define i32 @test_split_crit_edge(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_split_crit_edge( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[ENTRY_EXIT_CRIT_EDGE:%.*]], label [[A:%.*]] ; CHECK: entry.exit_crit_edge: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[ARG:%.*]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[ARG]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[ENTRY_EXIT_CRIT_EDGE]] ], [ [[SUM_1]], [[A]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag, label %exit, label %a a: br label %exit exit: %p = phi i32 [ 7, %entry ], [ 11, %a ] %sum = add i32 %arg, %p ret i32 %sum } define i32 @test_no_spec_dominating_inst(i1 %flag, i32* %ptr) { ; CHECK-LABEL: @test_no_spec_dominating_inst( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOAD:%.*]] = load i32, i32* [[PTR:%.*]] ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[LOAD]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[LOAD]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: %load = load i32, i32* %ptr br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %load, %p ret i32 %sum } ; We have special logic handling PHI nodes, make sure it doesn't get confused ; by a dominating PHI. define i32 @test_no_spec_dominating_phi(i1 %flag1, i1 %flag2, i32 %x, i32 %y) { ; CHECK-LABEL: @test_no_spec_dominating_phi( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG1:%.*]], label [[X_BLOCK:%.*]], label [[Y_BLOCK:%.*]] ; CHECK: x.block: ; CHECK-NEXT: br label [[MERGE:%.*]] ; CHECK: y.block: ; CHECK-NEXT: br label [[MERGE]] ; CHECK: merge: ; CHECK-NEXT: [[XY_PHI:%.*]] = phi i32 [ [[X:%.*]], [[X_BLOCK]] ], [ [[Y:%.*]], [[Y_BLOCK]] ] ; CHECK-NEXT: br i1 [[FLAG2:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[XY_PHI]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[XY_PHI]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag1, label %x.block, label %y.block x.block: br label %merge y.block: br label %merge merge: %xy.phi = phi i32 [ %x, %x.block ], [ %y, %y.block ] br i1 %flag2, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %xy.phi, %p ret i32 %sum } ; Ensure that we will speculate some number of "free" instructions on the given ; architecture even though they are unrelated to the PHI itself. define i32 @test_speculate_free_insts(i1 %flag, i64 %arg) { ; CHECK-LABEL: @test_speculate_free_insts( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[T1_0:%.*]] = trunc i64 [[ARG:%.*]] to i48 ; CHECK-NEXT: [[T2_0:%.*]] = trunc i48 [[T1_0]] to i32 ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[T2_0]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[T1_1:%.*]] = trunc i64 [[ARG]] to i48 ; CHECK-NEXT: [[T2_1:%.*]] = trunc i48 [[T1_1]] to i32 ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[T2_1]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %t1 = trunc i64 %arg to i48 %t2 = trunc i48 %t1 to i32 %sum = add i32 %t2, %p ret i32 %sum } define i32 @test_speculate_free_phis(i1 %flag, i32 %arg1, i32 %arg2) { ; CHECK-LABEL: @test_speculate_free_phis( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM_0:%.*]] = add i32 [[ARG1:%.*]], 7 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM_1:%.*]] = add i32 [[ARG2:%.*]], 11 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM_PHI:%.*]] = phi i32 [ [[SUM_0]], [[A]] ], [ [[SUM_1]], [[B]] ] ; CHECK-NEXT: [[P2:%.*]] = phi i32 [ [[ARG1]], [[A]] ], [ [[ARG2]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit ; We don't DCE the now unused PHI node... exit: %p1 = phi i32 [ 7, %a ], [ 11, %b ] %p2 = phi i32 [ %arg1, %a ], [ %arg2, %b ] %sum = add i32 %p2, %p1 ret i32 %sum } ; We shouldn't speculate multiple uses even if each individually looks ; profitable because of the total cost. define i32 @test_no_spec_multi_uses(i1 %flag, i32 %arg1, i32 %arg2, i32 %arg3) { ; CHECK-LABEL: @test_no_spec_multi_uses( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[A]] ], [ 11, [[B]] ] ; CHECK-NEXT: [[ADD1:%.*]] = add i32 [[ARG1:%.*]], [[P]] ; CHECK-NEXT: [[ADD2:%.*]] = add i32 [[ARG2:%.*]], [[P]] ; CHECK-NEXT: [[ADD3:%.*]] = add i32 [[ARG3:%.*]], [[P]] ; CHECK-NEXT: [[SUM1:%.*]] = add i32 [[ADD1]], [[ADD2]] ; CHECK-NEXT: [[SUM2:%.*]] = add i32 [[SUM1]], [[ADD3]] ; CHECK-NEXT: ret i32 [[SUM2]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %add1 = add i32 %arg1, %p %add2 = add i32 %arg2, %p %add3 = add i32 %arg3, %p %sum1 = add i32 %add1, %add2 %sum2 = add i32 %sum1, %add3 ret i32 %sum2 } define i32 @test_multi_phis1(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_multi_phis1( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM1_0:%.*]] = add i32 [[ARG:%.*]], 1 ; CHECK-NEXT: [[SUM2_0:%.*]] = add i32 [[SUM1_0]], 3 ; CHECK-NEXT: [[SUM3_0:%.*]] = add i32 [[SUM2_0]], 5 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM1_1:%.*]] = add i32 [[ARG]], 2 ; CHECK-NEXT: [[SUM2_1:%.*]] = add i32 [[SUM1_1]], 4 ; CHECK-NEXT: [[SUM3_1:%.*]] = add i32 [[SUM2_1]], 6 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM3_PHI:%.*]] = phi i32 [ [[SUM3_0]], [[A]] ], [ [[SUM3_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM3_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p1 = phi i32 [ 1, %a ], [ 2, %b ] %p2 = phi i32 [ 3, %a ], [ 4, %b ] %p3 = phi i32 [ 5, %a ], [ 6, %b ] %sum1 = add i32 %arg, %p1 %sum2 = add i32 %sum1, %p2 %sum3 = add i32 %sum2, %p3 ret i32 %sum3 } ; Check that the order of the PHIs doesn't impact the behavior. define i32 @test_multi_phis2(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_multi_phis2( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM1_0:%.*]] = add i32 [[ARG:%.*]], 1 ; CHECK-NEXT: [[SUM2_0:%.*]] = add i32 [[SUM1_0]], 3 ; CHECK-NEXT: [[SUM3_0:%.*]] = add i32 [[SUM2_0]], 5 ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM1_1:%.*]] = add i32 [[ARG]], 2 ; CHECK-NEXT: [[SUM2_1:%.*]] = add i32 [[SUM1_1]], 4 ; CHECK-NEXT: [[SUM3_1:%.*]] = add i32 [[SUM2_1]], 6 ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[SUM3_PHI:%.*]] = phi i32 [ [[SUM3_0]], [[A]] ], [ [[SUM3_1]], [[B]] ] ; CHECK-NEXT: ret i32 [[SUM3_PHI]] ; entry: br i1 %flag, label %a, label %b a: br label %exit b: br label %exit exit: %p3 = phi i32 [ 5, %a ], [ 6, %b ] %p2 = phi i32 [ 3, %a ], [ 4, %b ] %p1 = phi i32 [ 1, %a ], [ 2, %b ] %sum1 = add i32 %arg, %p1 %sum2 = add i32 %sum1, %p2 %sum3 = add i32 %sum2, %p3 ret i32 %sum3 } define i32 @test_no_spec_indirectbr(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_no_spec_indirectbr( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: indirectbr i8* undef, [label %exit] ; CHECK: b: ; CHECK-NEXT: indirectbr i8* undef, [label %exit] ; CHECK: exit: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[A]] ], [ 11, [[B]] ] ; CHECK-NEXT: [[SUM:%.*]] = add i32 [[ARG:%.*]], [[P]] ; CHECK-NEXT: ret i32 [[SUM]] ; entry: br i1 %flag, label %a, label %b a: indirectbr i8* undef, [label %exit] b: indirectbr i8* undef, [label %exit] exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %arg, %p ret i32 %sum } declare void @g() declare i32 @__gxx_personality_v0(...) ; FIXME: We should be able to handle this case -- only the exceptional edge is ; impossible to split. define i32 @test_no_spec_invoke_continue(i1 %flag, i32 %arg) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { ; CHECK-LABEL: @test_no_spec_invoke_continue( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[EXIT:%.*]] unwind label [[LPAD:%.*]] ; CHECK: b: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[EXIT]] unwind label [[LPAD]] ; CHECK: exit: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[A]] ], [ 11, [[B]] ] ; CHECK-NEXT: [[SUM:%.*]] = add i32 [[ARG:%.*]], [[P]] ; CHECK-NEXT: ret i32 [[SUM]] ; CHECK: lpad: ; CHECK-NEXT: [[LP:%.*]] = landingpad { i8*, i32 } ; CHECK-NEXT: cleanup ; CHECK-NEXT: resume { i8*, i32 } undef ; entry: br i1 %flag, label %a, label %b a: invoke void @g() to label %exit unwind label %lpad b: invoke void @g() to label %exit unwind label %lpad exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %sum = add i32 %arg, %p ret i32 %sum lpad: %lp = landingpad { i8*, i32 } cleanup resume { i8*, i32 } undef } define i32 @test_no_spec_landingpad(i32 %arg, i32* %ptr) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { ; CHECK-LABEL: @test_no_spec_landingpad( ; CHECK-NEXT: entry: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[INVOKE_CONT:%.*]] unwind label [[LPAD:%.*]] ; CHECK: invoke.cont: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[EXIT:%.*]] unwind label [[LPAD]] ; CHECK: lpad: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[ENTRY:%.*]] ], [ 11, [[INVOKE_CONT]] ] ; CHECK-NEXT: [[LP:%.*]] = landingpad { i8*, i32 } ; CHECK-NEXT: cleanup ; CHECK-NEXT: [[SUM:%.*]] = add i32 [[ARG:%.*]], [[P]] ; CHECK-NEXT: store i32 [[SUM]], i32* [[PTR:%.*]] ; CHECK-NEXT: resume { i8*, i32 } undef ; CHECK: exit: ; CHECK-NEXT: ret i32 0 ; entry: invoke void @g() to label %invoke.cont unwind label %lpad invoke.cont: invoke void @g() to label %exit unwind label %lpad lpad: %p = phi i32 [ 7, %entry ], [ 11, %invoke.cont ] %lp = landingpad { i8*, i32 } cleanup %sum = add i32 %arg, %p store i32 %sum, i32* %ptr resume { i8*, i32 } undef exit: ret i32 0 } declare i32 @__CxxFrameHandler3(...) define i32 @test_no_spec_cleanuppad(i32 %arg, i32* %ptr) personality i32 (...)* @__CxxFrameHandler3 { ; CHECK-LABEL: @test_no_spec_cleanuppad( ; CHECK-NEXT: entry: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[INVOKE_CONT:%.*]] unwind label [[LPAD:%.*]] ; CHECK: invoke.cont: ; CHECK-NEXT: invoke void @g() ; CHECK-NEXT: to label [[EXIT:%.*]] unwind label [[LPAD]] ; CHECK: lpad: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[ENTRY:%.*]] ], [ 11, [[INVOKE_CONT]] ] ; CHECK-NEXT: [[CP:%.*]] = cleanuppad within none [] ; CHECK-NEXT: [[SUM:%.*]] = add i32 [[ARG:%.*]], [[P]] ; CHECK-NEXT: store i32 [[SUM]], i32* [[PTR:%.*]] ; CHECK-NEXT: cleanupret from [[CP]] unwind to caller ; CHECK: exit: ; CHECK-NEXT: ret i32 0 ; entry: invoke void @g() to label %invoke.cont unwind label %lpad invoke.cont: invoke void @g() to label %exit unwind label %lpad lpad: %p = phi i32 [ 7, %entry ], [ 11, %invoke.cont ] %cp = cleanuppad within none [] %sum = add i32 %arg, %p store i32 %sum, i32* %ptr cleanupret from %cp unwind to caller exit: ret i32 0 } ; Check that we don't fall over when confronted with seemingly reasonable code ; for us to handle but in an unreachable region and with non-PHI use-def ; cycles. define i32 @test_unreachable_non_phi_cycles(i1 %flag, i32 %arg) { ; CHECK-LABEL: @test_unreachable_non_phi_cycles( ; CHECK-NEXT: entry: ; CHECK-NEXT: ret i32 42 ; CHECK: a: ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[P:%.*]] = phi i32 [ 7, [[A:%.*]] ], [ 11, [[B:%.*]] ] ; CHECK-NEXT: [[ZEXT:%.*]] = zext i32 [[SUM:%.*]] to i64 ; CHECK-NEXT: [[TRUNC:%.*]] = trunc i64 [[ZEXT]] to i32 ; CHECK-NEXT: [[SUM]] = add i32 [[TRUNC]], [[P]] ; CHECK-NEXT: br i1 [[FLAG:%.*]], label [[A]], label [[B]] ; entry: ret i32 42 a: br label %exit b: br label %exit exit: %p = phi i32 [ 7, %a ], [ 11, %b ] %zext = zext i32 %sum to i64 %trunc = trunc i64 %zext to i32 %sum = add i32 %trunc, %p br i1 %flag, label %a, label %b } ; Check that we don't speculate in the face of an expensive immediate. There ; are two reasons this should never speculate. First, even a local analysis ; should fail because it makes some paths (%a) potentially more expensive due ; to multiple uses of the immediate. Additionally, when we go to speculate the ; instructions, their cost will also be too high. ; FIXME: The goal is really to test the first property, but there doesn't ; happen to be any way to use free-to-speculate instructions here so that it ; would be the only interesting property. define i64 @test_expensive_imm(i32 %flag, i64 %arg) { ; CHECK-LABEL: @test_expensive_imm( ; CHECK-NEXT: entry: ; CHECK-NEXT: switch i32 [[FLAG:%.*]], label [[A:%.*]] [ ; CHECK-NEXT: i32 1, label [[B:%.*]] ; CHECK-NEXT: i32 2, label [[C:%.*]] ; CHECK-NEXT: i32 3, label [[D:%.*]] ; CHECK-NEXT: ] ; CHECK: a: ; CHECK-NEXT: br label [[EXIT:%.*]] ; CHECK: b: ; CHECK-NEXT: br label [[EXIT]] ; CHECK: c: ; CHECK-NEXT: br label [[EXIT]] ; CHECK: d: ; CHECK-NEXT: br label [[EXIT]] ; CHECK: exit: ; CHECK-NEXT: [[P:%.*]] = phi i64 [ 4294967296, [[A]] ], [ 1, [[B]] ], [ 1, [[C]] ], [ 1, [[D]] ] ; CHECK-NEXT: [[SUM1:%.*]] = add i64 [[ARG:%.*]], [[P]] ; CHECK-NEXT: [[SUM2:%.*]] = add i64 [[SUM1]], [[P]] ; CHECK-NEXT: ret i64 [[SUM2]] ; entry: switch i32 %flag, label %a [ i32 1, label %b i32 2, label %c i32 3, label %d ] a: br label %exit b: br label %exit c: br label %exit d: br label %exit exit: %p = phi i64 [ 4294967296, %a ], [ 1, %b ], [ 1, %c ], [ 1, %d ] %sum1 = add i64 %arg, %p %sum2 = add i64 %sum1, %p ret i64 %sum2 } define i32 @test_no_spec_non_postdominating_uses(i1 %flag1, i1 %flag2, i32 %arg) { ; CHECK-LABEL: @test_no_spec_non_postdominating_uses( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[FLAG1:%.*]], label [[A:%.*]], label [[B:%.*]] ; CHECK: a: ; CHECK-NEXT: [[SUM1_0:%.*]] = add i32 [[ARG:%.*]], 7 ; CHECK-NEXT: br label [[MERGE:%.*]] ; CHECK: b: ; CHECK-NEXT: [[SUM1_1:%.*]] = add i32 [[ARG]], 11 ; CHECK-NEXT: br label [[MERGE]] ; CHECK: merge: ; CHECK-NEXT: [[SUM1_PHI:%.*]] = phi i32 [ [[SUM1_0]], [[A]] ], [ [[SUM1_1]], [[B]] ] ; CHECK-NEXT: [[P2:%.*]] = phi i32 [ 13, [[A]] ], [ 42, [[B]] ] ; CHECK-NEXT: br i1 [[FLAG2:%.*]], label [[EXIT1:%.*]], label [[EXIT2:%.*]] ; CHECK: exit1: ; CHECK-NEXT: ret i32 [[SUM1_PHI]] ; CHECK: exit2: ; CHECK-NEXT: [[SUM2:%.*]] = add i32 [[ARG]], [[P2]] ; CHECK-NEXT: ret i32 [[SUM2]] ; entry: br i1 %flag1, label %a, label %b a: br label %merge b: br label %merge merge: %p1 = phi i32 [ 7, %a ], [ 11, %b ] %p2 = phi i32 [ 13, %a ], [ 42, %b ] %sum1 = add i32 %arg, %p1 br i1 %flag2, label %exit1, label %exit2 exit1: ret i32 %sum1 exit2: %sum2 = add i32 %arg, %p2 ret i32 %sum2 }