From 8699921c4b7a18c5809b38b45a3ac618826c6bf8 Mon Sep 17 00:00:00 2001 From: Kyle Butt Date: Fri, 2 Sep 2016 18:29:26 +0000 Subject: [PATCH] IfConversion: Fix bug introduced by rescanning diamonds. Passing the wrong values for predicate-clobbering. Simple to miss. Added an assert to make this easier to catch in the future. llvm-svn: 280517 --- llvm/lib/CodeGen/IfConversion.cpp | 2 +- .../CodeGen/Thumb2/ifcvt-rescan-diamonds.ll | 66 +++++++++++++++++++ 2 files changed, 67 insertions(+), 1 deletion(-) create mode 100644 llvm/test/CodeGen/Thumb2/ifcvt-rescan-diamonds.ll diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp index 76b4f3432a65..3f74ff850652 100644 --- a/llvm/lib/CodeGen/IfConversion.cpp +++ b/llvm/lib/CodeGen/IfConversion.cpp @@ -1982,7 +1982,7 @@ bool IfConverter::IfConvertDiamond(BBInfo &BBI, IfcvtKind Kind, if (!IfConvertDiamondCommon( BBI, TrueBBI, FalseBBI, NumDups1, NumDups2, - TrueBBI.ClobbersPred, FalseBBI.ClobbersPred, + TClobbersPred, FClobbersPred, /* RemoveBranch */ TrueBBI.IsBrAnalyzable, /* MergeAddEdges */ TailBB == nullptr)) return false; diff --git a/llvm/test/CodeGen/Thumb2/ifcvt-rescan-diamonds.ll b/llvm/test/CodeGen/Thumb2/ifcvt-rescan-diamonds.ll new file mode 100644 index 000000000000..b7ba741b2498 --- /dev/null +++ b/llvm/test/CodeGen/Thumb2/ifcvt-rescan-diamonds.ll @@ -0,0 +1,66 @@ +; RUN: llc -O2 -o - %s | FileCheck %s +target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64" +target triple = "thumbv8-unknown-linux-gnueabihf" + +; This is a tricky test case. +; The point of it is to create a diamond where both the true block and the +; false block clobber the predicate when viewed as a whole, but only one of them +; clobbers the predicate when considering the instructions they share. + +; Function Attrs: nounwind +define void @BN_kronecker(i1 %a, i32 %b) #0 { +entry: + br label %while.cond38 + +while.cond38: ; preds = %if.end111, %entry + %cmp79 = icmp eq i32 0, 0 + br i1 %a, label %cond.true77, label %cond.false87 + +; CHECK: %cond.true77 +; CHECK-NEXT: @ in Loop +; CHECK-NEXT: cmp.w {{r[0-9]+}}, #0 +; CHECK-NEXT: it eq +; CHECK-NEXT: ldreq +; CHECK-NEXT: it ne +; CHECK-NEXT: movsne +; CHECK-NEXT: mvns +; CHECK-NEXT: b +cond.true77: ; preds = %while.cond38 + br i1 %cmp79, label %cond.end84, label %cond.false81 + +cond.false81: ; preds = %cond.true77 + %0 = load i32, i32* null, align 4 + br label %cond.end84 + +cond.end84: ; preds = %cond.false81, %cond.true77 + %cond85 = phi i32 [ %0, %cond.false81 ], [ 0, %cond.true77 ] + %neg86 = xor i32 %cond85, -1 + br label %cond.false101 + +cond.false87: ; preds = %while.cond38 + br i1 %cmp79, label %cond.false101, label %cond.false91 + +cond.false91: ; preds = %cond.false87 + br label %cond.false101 + +cond.false101: ; preds = %cond.false91, %cond.false87, %cond.end84 + %cond97 = phi i32 [ %neg86, %cond.end84 ], [ %b, %cond.false91 ], [ 0, %cond.false87 ] + %1 = load i32, i32* null, align 4 + %and106 = and i32 %cond97, %1 + %and107 = and i32 %and106, 2 + %tobool108 = icmp ne i32 %and107, 0 + br i1 %tobool108, label %if.then109, label %if.end111 + +if.then109: ; preds = %cond.false101 + store i32 0, i32* undef, align 4 + br label %if.end111 + +if.end111: ; preds = %if.then109, %cond.false101 + %tobool113 = icmp ne i32 0, 0 + br i1 %tobool113, label %while.cond38, label %end + +end: ; preds = %if.end111 + ret void +} + +attributes #0 = { nounwind }