| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt -S -indvars < %s | FileCheck %s |
| |
| ; Tests in this file are specifically about correctly handling possibly poison |
| ; producing flags when converting from one IV to another. In particular, there |
| ; is a risk that the IV we chose to switch to is dynamically dead (i.e. there |
| ; is no side effect which dependents on the computation thereof). Such an IV |
| ; can produce poison on one or more iterations without triggering UB. When we |
| ; add an additional use to such an IV, we need to ensure that our new use does |
| ; not trigger UB where none existed in the original program. |
| |
| ; Provide legal integer types. |
| target datalayout = "n8:16:32:64" |
| |
| @data = common global [240 x i8] zeroinitializer, align 16 |
| |
| ;; In this example, the pointer IV is dynamicaly dead. As such, the fact that |
| ;; inbounds produces poison *does not* trigger UB in the original loop. As |
| ;; such, the pointer IV can be poison and adding a new use of the pointer |
| ;; IV which dependends on that poison computation in a manner which might |
| ;; trigger UB would be incorrect. |
| ;; FIXME: This currently shows a miscompile! |
| define void @neg_dynamically_dead_inbounds(i1 %always_false) #0 { |
| ; CHECK-LABEL: @neg_dynamically_dead_inbounds( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[I_0:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[TMP4:%.*]], [[CONT:%.*]] ] |
| ; CHECK-NEXT: [[P_0:%.*]] = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), [[ENTRY]] ], [ [[TMP3:%.*]], [[CONT]] ] |
| ; CHECK-NEXT: [[TMP3]] = getelementptr inbounds i8, i8* [[P_0]], i64 1 |
| ; CHECK-NEXT: br i1 [[ALWAYS_FALSE:%.*]], label [[NEVER_EXECUTED:%.*]], label [[CONT]] |
| ; CHECK: never_executed: |
| ; CHECK-NEXT: store volatile i8 0, i8* [[TMP3]] |
| ; CHECK-NEXT: br label [[CONT]] |
| ; CHECK: cont: |
| ; CHECK-NEXT: [[TMP4]] = add nuw i8 [[I_0]], 1 |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8 [[TMP4]], -10 |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %cont ] |
| %p.0 = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), %entry ], [ %tmp3, %cont ] |
| %tmp3 = getelementptr inbounds i8, i8* %p.0, i64 1 |
| br i1 %always_false, label %never_executed, label %cont |
| |
| never_executed: |
| store volatile i8 0, i8* %tmp3 |
| br label %cont |
| |
| cont: |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret void |
| } |
| |
| ; Similiar to above, but shows how we currently guard non-constant |
| ; memory operands in a manner which hides the latent miscompile. |
| define void @neg_dynamically_dead_inbounds2(i8* %a, i1 %always_false) #0 { |
| ; CHECK-LABEL: @neg_dynamically_dead_inbounds2( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[I_0:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[TMP4:%.*]], [[CONT:%.*]] ] |
| ; CHECK-NEXT: [[P_0:%.*]] = phi i8* [ [[A:%.*]], [[ENTRY]] ], [ [[TMP3:%.*]], [[CONT]] ] |
| ; CHECK-NEXT: [[TMP3]] = getelementptr inbounds i8, i8* [[P_0]], i64 1 |
| ; CHECK-NEXT: br i1 [[ALWAYS_FALSE:%.*]], label [[NEVER_EXECUTED:%.*]], label [[CONT]] |
| ; CHECK: never_executed: |
| ; CHECK-NEXT: store volatile i8 0, i8* [[TMP3]] |
| ; CHECK-NEXT: br label [[CONT]] |
| ; CHECK: cont: |
| ; CHECK-NEXT: [[TMP4]] = add nuw i8 [[I_0]], 1 |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8 [[TMP4]], -10 |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %cont ] |
| %p.0 = phi i8* [ %a, %entry ], [ %tmp3, %cont ] |
| %tmp3 = getelementptr inbounds i8, i8* %p.0, i64 1 |
| br i1 %always_false, label %never_executed, label %cont |
| |
| never_executed: |
| store volatile i8 0, i8* %tmp3 |
| br label %cont |
| |
| cont: |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret void |
| } |
| |
| define void @dom_store_preinc() #0 { |
| ; CHECK-LABEL: @dom_store_preinc( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[P_0:%.*]] = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: store volatile i8 0, i8* [[P_0]] |
| ; CHECK-NEXT: [[TMP3]] = getelementptr inbounds i8, i8* [[P_0]], i64 1 |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8* [[P_0]], getelementptr ([240 x i8], [240 x i8]* @data, i64 1, i64 5) |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %loop ] |
| %p.0 = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), %entry ], [ %tmp3, %loop ] |
| store volatile i8 0, i8* %p.0 |
| %tmp3 = getelementptr inbounds i8, i8* %p.0, i64 1 |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret void |
| } |
| |
| define void @dom_store_postinc() #0 { |
| ; CHECK-LABEL: @dom_store_postinc( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[P_0:%.*]] = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: [[TMP3]] = getelementptr inbounds i8, i8* [[P_0]], i64 1 |
| ; CHECK-NEXT: store volatile i8 0, i8* [[TMP3]] |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8* [[TMP3]], getelementptr ([240 x i8], [240 x i8]* @data, i64 1, i64 6) |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %loop ] |
| %p.0 = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), %entry ], [ %tmp3, %loop ] |
| %tmp3 = getelementptr inbounds i8, i8* %p.0, i64 1 |
| store volatile i8 0, i8* %tmp3 |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret void |
| } |
| |
| define i8 @dom_load() #0 { |
| ; CHECK-LABEL: @dom_load( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[P_0:%.*]] = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: [[TMP3]] = getelementptr inbounds i8, i8* [[P_0]], i64 1 |
| ; CHECK-NEXT: [[V:%.*]] = load i8, i8* [[TMP3]] |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8* [[TMP3]], getelementptr ([240 x i8], [240 x i8]* @data, i64 1, i64 6) |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: [[V_LCSSA:%.*]] = phi i8 [ [[V]], [[LOOP]] ] |
| ; CHECK-NEXT: ret i8 [[V_LCSSA]] |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %loop ] |
| %p.0 = phi i8* [ getelementptr inbounds ([240 x i8], [240 x i8]* @data, i64 0, i64 0), %entry ], [ %tmp3, %loop ] |
| %tmp3 = getelementptr inbounds i8, i8* %p.0, i64 1 |
| %v = load i8, i8* %tmp3 |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret i8 %v |
| } |
| |
| define i64 @dom_div(i64 %input) #0 { |
| ; CHECK-LABEL: @dom_div( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[I_0:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[TMP4:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: [[I_1:%.*]] = phi i64 [ [[INPUT:%.*]], [[ENTRY]] ], [ [[TMP3:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: [[TMP3]] = add nuw nsw i64 [[I_1]], 1 |
| ; CHECK-NEXT: [[V:%.*]] = udiv i64 5, [[TMP3]] |
| ; CHECK-NEXT: [[TMP4]] = add nuw i8 [[I_0]], 1 |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i8 [[TMP4]], -10 |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: [[V_LCSSA:%.*]] = phi i64 [ [[V]], [[LOOP]] ] |
| ; CHECK-NEXT: ret i64 [[V_LCSSA]] |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %loop ] |
| %i.1 = phi i64 [ %input, %entry ], [ %tmp3, %loop ] |
| %tmp3 = add nsw nuw i64 %i.1, 1 |
| %v = udiv i64 5, %tmp3 |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret i64 %v |
| } |
| |
| ; For integer IVs, we handle this trigger case by stripping the problematic |
| ; flags which removes the potential introduction of UB. |
| define void @neg_dead_int_iv() #0 { |
| ; CHECK-LABEL: @neg_dead_int_iv( |
| ; CHECK-NEXT: entry: |
| ; CHECK-NEXT: br label [[LOOP:%.*]] |
| ; CHECK: loop: |
| ; CHECK-NEXT: [[I_1:%.*]] = phi i64 [ -2, [[ENTRY:%.*]] ], [ [[TMP3:%.*]], [[LOOP]] ] |
| ; CHECK-NEXT: [[TMP3]] = add nsw i64 [[I_1]], 1 |
| ; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[TMP3]], 244 |
| ; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT:%.*]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| entry: |
| br label %loop |
| |
| loop: |
| %i.0 = phi i8 [ 0, %entry ], [ %tmp4, %loop ] |
| %i.1 = phi i64 [ -2, %entry ], [ %tmp3, %loop ] |
| %tmp3 = add nsw nuw i64 %i.1, 1 |
| %tmp4 = add i8 %i.0, 1 |
| %tmp5 = icmp ult i8 %tmp4, -10 |
| br i1 %tmp5, label %loop, label %exit |
| |
| exit: |
| ret void |
| } |
| |