; RUN: opt < %s -simplifycfg -phi-node-folding-threshold=2 -S | FileCheck %s target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" define i32 @test1(i32 %a, i32 %b, i32 %c) nounwind { ; CHECK: @test1 entry: %tmp1 = icmp eq i32 %b, 0 br i1 %tmp1, label %bb1, label %bb3 bb1: ; preds = %entry %tmp2 = icmp sgt i32 %c, 1 br i1 %tmp2, label %bb2, label %bb3 ; CHECK: bb1: ; CHECK-NEXT: icmp sgt i32 %c, 1 ; CHECK-NEXT: add i32 %a, 1 ; CHECK-NEXT: select i1 %tmp2, i32 %tmp3, i32 %a ; CHECK-NEXT: br label %bb3 bb2: ; preds = bb1 %tmp3 = add i32 %a, 1 br label %bb3 bb3: ; preds = %bb2, %entry %tmp4 = phi i32 [ %b, %entry ], [ %a, %bb1 ], [ %tmp3, %bb2 ] %tmp5 = sub i32 %tmp4, 1 ret i32 %tmp5 } declare i8 @llvm.cttz.i8(i8, i1) define i8 @test2(i8 %a) { ; CHECK: @test2 br i1 undef, label %bb_true, label %bb_false bb_true: %b = tail call i8 @llvm.cttz.i8(i8 %a, i1 false) br label %join bb_false: br label %join join: %c = phi i8 [%b, %bb_true], [%a, %bb_false] ; CHECK: select ret i8 %c } define i8* @test3(i1* %dummy, i8* %a, i8* %b) { ; Test that a weird, unfolded constant cast in the PHI don't block speculation. ; CHECK: @test3 entry: %cond1 = load volatile i1* %dummy br i1 %cond1, label %if, label %end if: %cond2 = load volatile i1* %dummy br i1 %cond2, label %then, label %end then: br label %end end: %x = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 42 to i8*), %then ] ; CHECK-NOT: phi ; CHECK: select i1 %cond2, i8* inttoptr ret i8* %x } define i8* @test4(i1* %dummy, i8* %a, i8* %b) { ; Test that we don't speculate an arbitrarily large number of unfolded constant ; expressions. ; CHECK: @test4 entry: %cond1 = load volatile i1* %dummy br i1 %cond1, label %if, label %end if: %cond2 = load volatile i1* %dummy br i1 %cond2, label %then, label %end then: br label %end end: %x1 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 1 to i8*), %then ] %x2 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 2 to i8*), %then ] %x3 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 3 to i8*), %then ] %x4 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 4 to i8*), %then ] %x5 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 5 to i8*), %then ] %x6 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 6 to i8*), %then ] %x7 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 7 to i8*), %then ] %x8 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 8 to i8*), %then ] %x9 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 9 to i8*), %then ] %x10 = phi i8* [ %a, %entry ], [ %b, %if ], [ inttoptr (i64 10 to i8*), %then ] ; CHECK-NOT: select ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ; CHECK: phi i8* ret i8* %x10 } define i16 @test5(i1* %dummy, i16 %a, i16 %b) { ; Test that we speculate no-op instructions. ; CHECK: @test5 entry: %cond1 = load volatile i1* %dummy br i1 %cond1, label %if, label %end if: %cond2 = load volatile i1* %dummy %a.conv = sext i16 %a to i32 %b.conv = sext i16 %b to i32 %cmp = icmp ult i32 %a.conv, %b.conv br i1 %cond2, label %then, label %end then: %sub = sub i32 %a.conv, %b.conv %sub.conv = trunc i32 %sub to i16 br label %end end: %x = phi i16 [ %a, %entry ], [ %b, %if ], [ %sub.conv, %then ] ; CHECK-NOT: phi ; CHECK: select i1 ret i16 %x } define i16 @test6(i1* %dummy, i64 %a, i64 %b) { ; Test that we speculate no-op instructions when those instructions are in the ; predecessor but could potentially be sunk. ; CHECK: @test6 entry: %cond1 = load volatile i1* %dummy %a.conv = trunc i64 %a to i16 %b.conv = trunc i64 %b to i16 br i1 %cond1, label %if, label %end if: %cond2 = load volatile i1* %dummy %cond3 = load volatile i1* %dummy %cond4 = load volatile i1* %dummy %cmp = icmp ult i16 %a.conv, %b.conv %a.conv2 = trunc i64 %a to i32 %b.conv2 = trunc i64 %b to i32 br i1 %cond2, label %then, label %end then: %sub = sub i32 %a.conv2, %b.conv2 %sub.conv = trunc i32 %sub to i16 br label %end end: %x = phi i16 [ %a.conv, %entry ], [ %b.conv, %if ], [ %sub.conv, %then ] ; CHECK-NOT: phi ; CHECK: select i1 ret i16 %x } define i16 @test7(i1* %dummy, i16 %a, i16 %b, i32 %x) { ; Test that we don't speculate when there are instructions that could ; potentially sink into the conditional block. ; CHECK: @test7 entry: %cond1 = load volatile i1* %dummy br i1 %cond1, label %if, label %end if: %cond2 = load volatile i1* %dummy %a.conv = sext i16 %a to i32 %b.conv = sext i16 %b to i32 %cmp = icmp ult i32 %a.conv, %b.conv %a.conv2 = add i32 %a.conv, %x br i1 %cond2, label %then, label %end then: %sub = sub i32 %a.conv2, %b.conv %sub.conv = trunc i32 %sub to i16 br label %end end: %y = phi i16 [ %a, %entry ], [ %b, %if ], [ %sub.conv, %then ] ; CHECK-NOT: select ; CHECK: phi i16 ret i16 %y }