diff options
| -rw-r--r-- | lib/CodeGen/IfConversion.cpp | 6 | ||||
| -rw-r--r-- | test/CodeGen/ARM/2013-05-05-IfConvertBug.ll | 59 |
2 files changed, 62 insertions, 3 deletions
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp index f4485d5d9a..1ae7e3b5ca 100644 --- a/lib/CodeGen/IfConversion.cpp +++ b/lib/CodeGen/IfConversion.cpp @@ -720,9 +720,9 @@ bool IfConverter::FeasibilityAnalysis(BBInfo &BBI, if (BBI.IsDone || BBI.IsUnpredicable) return false; - // If it is already predicated, check if its predicate subsumes the new - // predicate. - if (BBI.Predicate.size() && !TII->SubsumesPredicate(BBI.Predicate, Pred)) + // If it is already predicated, check if the new predicate subsumes + // its predicate. + if (BBI.Predicate.size() && !TII->SubsumesPredicate(Pred, BBI.Predicate)) return false; if (BBI.BrCond.size()) { diff --git a/test/CodeGen/ARM/2013-05-05-IfConvertBug.ll b/test/CodeGen/ARM/2013-05-05-IfConvertBug.ll index 3f054c64b8..2eeebac993 100644 --- a/test/CodeGen/ARM/2013-05-05-IfConvertBug.ll +++ b/test/CodeGen/ARM/2013-05-05-IfConvertBug.ll @@ -69,3 +69,62 @@ bb6.i350: ; preds = %bb2.i KBBlockZero.exit: ; preds = %bb2.i indirectbr i8* undef, [label %KBBlockZero_return_1, label %KBBlockZero_return_0] } + + +; If-converter was checking for the wrong predicate subsumes pattern when doing +; nested predicates. +; E.g., Let A be a basic block that flows conditionally into B and B be a +; predicated block. +; B can be predicated with A.BrToBPredicate into A iff B.Predicate is less +; "permissive" than A.BrToBPredicate, i.e., iff A.BrToBPredicate subsumes +; B.Predicate. +; <rdar://problem/14379453> + +; Hard-coded registers comes from the ABI. +; CHECK: wrapDistance: +; CHECK: cmp r1, #59 +; CHECK-NEXT: itt le +; CHECK-NEXT: suble r0, r2, #1 +; CHECK-NEXT: bxle lr +; CHECK-NEXT: subs [[REG:r[0-9]+]], #120 +; CHECK-NEXT: cmp [[REG]], r1 +; CHECK-NOT: it lt +; CHECK-NEXT: bge [[LABEL:.+]] +; Next BB +; CHECK-NOT: cmplt +; CHECK: cmp r0, #119 +; CHECK-NEXT: itt le +; CHECK-NEXT: addle r0, r1, #1 +; CHECK-NEXT: bxle lr +; Next BB +; CHECK: [[LABEL]]: +; CHECK-NEXT: subs r0, r1, r0 +; CHECK-NEXT: bx lr +define i32 @wrapDistance(i32 %tx, i32 %sx, i32 %w) { +entry: + %cmp = icmp slt i32 %sx, 60 + br i1 %cmp, label %if.then, label %if.else + +if.then: ; preds = %entry + %sub = add nsw i32 %w, -1 + br label %return + +if.else: ; preds = %entry + %sub1 = add nsw i32 %w, -120 + %cmp2 = icmp slt i32 %sub1, %sx + %cmp3 = icmp slt i32 %tx, 120 + %or.cond = and i1 %cmp2, %cmp3 + br i1 %or.cond, label %if.then4, label %if.end5 + +if.then4: ; preds = %if.else + %add = add nsw i32 %sx, 1 + br label %return + +if.end5: ; preds = %if.else + %sub6 = sub nsw i32 %sx, %tx + br label %return + +return: ; preds = %if.end5, %if.then4, %if.then + %retval.0 = phi i32 [ %sub, %if.then ], [ %add, %if.then4 ], [ %sub6, %if.end5 ] + ret i32 %retval.0 +} |