From dbcfb3080a1e208aef8e4f13a94ce3aa8309643f Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Fri, 10 Apr 2009 10:09:34 +0000 Subject: [PATCH] Don't fold a load if the other operand is a TLS address. With this we generate movl %gs:0, %eax leal i@NTPOFF(%eax), %eax instead of movl $i@NTPOFF, %eax addl %gs:0, %eax git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68778 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86ISelDAGToDAG.cpp | 33 ++++++++++++++++++++++++------ test/CodeGen/X86/tls10.ll | 4 ++-- test/CodeGen/X86/tls15.ll | 14 +++++++++++++ test/CodeGen/X86/tls2.ll | 4 ++-- test/CodeGen/X86/tls6.ll | 4 ++-- test/CodeGen/X86/tls8.ll | 4 ++-- 6 files changed, 49 insertions(+), 14 deletions(-) create mode 100644 test/CodeGen/X86/tls15.ll diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp index 2cd6f74f27e..1b9572cc412 100644 --- a/lib/Target/X86/X86ISelDAGToDAG.cpp +++ b/lib/Target/X86/X86ISelDAGToDAG.cpp @@ -322,6 +322,8 @@ bool X86DAGToDAGISel::IsLegalAndProfitableToFold(SDNode *N, SDNode *U, case ISD::AND: case ISD::OR: case ISD::XOR: { + SDValue Op1 = U->getOperand(1); + // If the other operand is a 8-bit immediate we should fold the immediate // instead. This reduces code size. // e.g. @@ -332,9 +334,25 @@ bool X86DAGToDAGISel::IsLegalAndProfitableToFold(SDNode *N, SDNode *U, // addl 4(%esp), %eax // The former is 2 bytes shorter. In case where the increment is 1, then // the saving can be 4 bytes (by using incl %eax). - if (ConstantSDNode *Imm = dyn_cast(U->getOperand(1))) + if (ConstantSDNode *Imm = dyn_cast(Op1)) if (Imm->getAPIntValue().isSignedIntN(8)) return false; + + // If the other operand is a TLS address, we should fold it instead. + // This produces + // movl %gs:0, %eax + // leal i@NTPOFF(%eax), %eax + // instead of + // movl $i@NTPOFF, %eax + // addl %gs:0, %eax + // if the block also has an access to a second TLS address this will save + // a load. + // FIXME: This is probably also true for non TLS addresses. + if (Op1.getOpcode() == X86ISD::Wrapper) { + SDValue Val = Op1.getOperand(0); + if (Val.getOpcode() == ISD::TargetGlobalTLSAddress) + return false; + } } } @@ -1170,13 +1188,16 @@ bool X86DAGToDAGISel::SelectLEAAddr(SDValue Op, SDValue N, SDValue &Base, SDValue &Scale, SDValue &Index, SDValue &Disp) { X86ISelAddressMode AM; - if (MatchAddress(N, AM)) - return false; - //Is it better to set AM.Segment before calling MatchAddress to - //prevent it from adding a segment? - if (AM.Segment.getNode()) + // Set AM.Segment to prevent MatchAddress from using one. LEA doesn't support + // segments. + SDValue Copy = AM.Segment; + SDValue T = CurDAG->getRegister(0, MVT::i32); + AM.Segment = T; + if (MatchAddress(N, AM)) return false; + assert (T == AM.Segment); + AM.Segment = Copy; MVT VT = N.getValueType(); unsigned Complexity = 0; diff --git a/test/CodeGen/X86/tls10.ll b/test/CodeGen/X86/tls10.ll index 5f022e3992b..a4f2fb1293b 100644 --- a/test/CodeGen/X86/tls10.ll +++ b/test/CodeGen/X86/tls10.ll @@ -1,6 +1,6 @@ ; RUN: llvm-as < %s | llc -march=x86 -mtriple=i386-linux-gnu > %t -; RUN: grep {movl \$i@NTPOFF, %eax} %t -; RUN: grep {addl %gs:0, %eax} %t +; RUN: grep {movl %gs:0, %eax} %t +; RUN: grep {leal i@NTPOFF(%eax), %eax} %t @i = external hidden thread_local global i32 diff --git a/test/CodeGen/X86/tls15.ll b/test/CodeGen/X86/tls15.ll new file mode 100644 index 00000000000..5d3ee16a476 --- /dev/null +++ b/test/CodeGen/X86/tls15.ll @@ -0,0 +1,14 @@ +; RUN: llvm-as < %s | llc -march=x86 -mtriple=i386-linux-gnu > %t +; RUN: grep {movl %gs:0, %eax} %t | count 1 +; RUN: grep {leal i@NTPOFF(%eax), %ecx} %t +; RUN: grep {leal j@NTPOFF(%eax), %eax} %t + +@i = thread_local global i32 0 +@j = thread_local global i32 0 + +define void @f(i32** %a, i32** %b) { +entry: + store i32* @i, i32** %a, align 8 + store i32* @j, i32** %b, align 8 + ret void +} diff --git a/test/CodeGen/X86/tls2.ll b/test/CodeGen/X86/tls2.ll index 8edc64ffba4..fb57ae1a391 100644 --- a/test/CodeGen/X86/tls2.ll +++ b/test/CodeGen/X86/tls2.ll @@ -1,6 +1,6 @@ ; RUN: llvm-as < %s | llc -march=x86 -mtriple=i386-linux-gnu > %t -; RUN: grep {movl \$i@NTPOFF, %eax} %t -; RUN: grep {addl %gs:0, %eax} %t +; RUN: grep {movl %gs:0, %eax} %t +; RUN: grep {leal i@NTPOFF(%eax), %eax} %t @i = thread_local global i32 15 diff --git a/test/CodeGen/X86/tls6.ll b/test/CodeGen/X86/tls6.ll index fc10a57cc1b..e0bcade8dd8 100644 --- a/test/CodeGen/X86/tls6.ll +++ b/test/CodeGen/X86/tls6.ll @@ -1,6 +1,6 @@ ; RUN: llvm-as < %s | llc -march=x86 -mtriple=i386-linux-gnu > %t -; RUN: grep {movl \$i@NTPOFF, %eax} %t -; RUN: grep {addl %gs:0, %eax} %t +; RUN: grep {movl %gs:0, %eax} %t +; RUN: grep {leal i@NTPOFF(%eax), %eax} %t @i = internal thread_local global i32 15 diff --git a/test/CodeGen/X86/tls8.ll b/test/CodeGen/X86/tls8.ll index fb570b0118e..4971fd23ba6 100644 --- a/test/CodeGen/X86/tls8.ll +++ b/test/CodeGen/X86/tls8.ll @@ -1,6 +1,6 @@ ; RUN: llvm-as < %s | llc -march=x86 -mtriple=i386-linux-gnu > %t -; RUN: grep {movl \$i@NTPOFF, %eax} %t -; RUN: grep {addl %gs:0, %eax} %t +; RUN: grep {movl %gs:0, %eax} %t +; RUN: grep {leal i@NTPOFF(%eax), %eax} %t @i = hidden thread_local global i32 15 -- 2.34.1