From d26c93d3a8a484c5b42f06163ae5de787f0ac276 Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Mon, 13 May 2013 10:21:19 +0000 Subject: [PATCH] Correctly preserve the input chain for potential tailcall nodes whose return values are bitcasts. The chain had previously been being clobbered with the entry node to the dag, which sometimes caused other code in the function to be erroneously deleted when tailcall optimization kicked in. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181696 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMISelLowering.cpp | 2 +- test/CodeGen/ARM/call-tc.ll | 17 +++++++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index fd777323642..008edbe4a75 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -2147,7 +2147,7 @@ bool ARMTargetLowering::isUsedByReturnOnly(SDNode *N, SDValue &Chain) const { Copy = *Copy->use_begin(); if (Copy->getOpcode() != ISD::CopyToReg || !Copy->hasNUsesOfValue(1, 0)) return false; - Chain = Copy->getOperand(0); + TCChain = Copy->getOperand(0); } else { return false; } diff --git a/test/CodeGen/ARM/call-tc.ll b/test/CodeGen/ARM/call-tc.ll index 58fbbda0f6b..c7e17ea353f 100644 --- a/test/CodeGen/ARM/call-tc.ll +++ b/test/CodeGen/ARM/call-tc.ll @@ -162,3 +162,20 @@ define i32 @t9() nounwind { declare %class.MutexLock* @_ZN9MutexLockC1Ev(%class.MutexLock*) unnamed_addr nounwind align 2 declare %class.MutexLock* @_ZN9MutexLockD1Ev(%class.MutexLock*) unnamed_addr nounwind align 2 + +; rdar://13827621 +; Correctly preserve the input chain for the tailcall node in the bitcast case, +; otherwise the call to floorf is lost. +define float @libcall_tc_test2(float* nocapture %a, float %b) { +; CHECKT2D: libcall_tc_test2: +; CHECKT2D: blx _floorf +; CHECKT2D: b.w _truncf + %1 = load float* %a, align 4 + %call = tail call float @floorf(float %1) + store float %call, float* %a, align 4 + %call1 = tail call float @truncf(float %b) + ret float %call1 +} + +declare float @floorf(float) readnone +declare float @truncf(float) readnone