[llvm] r278954 - Fix for PR29010

[Marina Yatsina via llvm-commits]

Author: myatsina
Date: Wed Aug 17 14:07:40 2016
New Revision: 278954

URL: http://llvm.org/viewvc/llvm-project?rev=278954&view=rev
Log:
Fix for PR29010

This is a fix for https://llvm.org/bugs/show_bug.cgi?id=29010
Root cause of the bug is that the register class of the machine instruction operand does not fully reflect if this registers that can be allocated.
Both for i386 and x86_64 the operand's register class is VR128RegClass and thus contains xmm0-xmm15, though in i386 we can only use xmm0-xmm8.
In order to get the actual allocable registers of the class we need to use RegisterClassInfo.

Differential Revision: https://reviews.llvm.org/D23613


Added:
    llvm/trunk/test/CodeGen/X86/pr29010.ll
Modified:
    llvm/trunk/lib/CodeGen/ExecutionDepsFix.cpp

Modified: llvm/trunk/lib/CodeGen/ExecutionDepsFix.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ExecutionDepsFix.cpp?rev=278954&r1=278953&r2=278954&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ExecutionDepsFix.cpp (original)
+++ llvm/trunk/lib/CodeGen/ExecutionDepsFix.cpp Wed Aug 17 14:07:40 2016
@@ -26,6 +26,7 @@
 #include "llvm/CodeGen/LivePhysRegs.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterClassInfo.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
@@ -137,6 +138,7 @@ class ExeDepsFix : public MachineFunctio
   MachineFunction *MF;
   const TargetInstrInfo *TII;
   const TargetRegisterInfo *TRI;
+  RegisterClassInfo RegClassInfo;
   std::vector<SmallVector<int, 1>> AliasMap;
   const unsigned NumRegs;
   LiveReg *LiveRegs;
@@ -509,7 +511,8 @@ void ExeDepsFix::pickBestRegisterForUnde
   // max clearance or clearance higher than Pref.
   unsigned MaxClearance = 0;
   unsigned MaxClearanceReg = OriginalReg;
-  for (auto Reg : OpRC->getRegisters()) {
+  ArrayRef<MCPhysReg> Order = RegClassInfo.getOrder(OpRC);
+  for (auto Reg : Order) {
     assert(AliasMap[Reg].size() == 1 &&
            "Reg is expected to be mapped to a single index");
     int RCrx = *regIndices(Reg).begin();
@@ -785,6 +788,7 @@ bool ExeDepsFix::runOnMachineFunction(Ma
   MF = &mf;
   TII = MF->getSubtarget().getInstrInfo();
   TRI = MF->getSubtarget().getRegisterInfo();
+  RegClassInfo.runOnMachineFunction(mf);
   LiveRegs = nullptr;
   assert(NumRegs == RC->getNumRegs() && "Bad regclass");
 

Added: llvm/trunk/test/CodeGen/X86/pr29010.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr29010.ll?rev=278954&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pr29010.ll (added)
+++ llvm/trunk/test/CodeGen/X86/pr29010.ll Wed Aug 17 14:07:40 2016
@@ -0,0 +1,12 @@
+; RUN: llc < %s -mtriple=i386-linux -mattr=+avx | FileCheck %s
+
+; In i386 there are only 8 XMMs (xmm0-xmm7), make sure we we are not creating illegal XMM
+define float @only_xmm0_7(i32 %arg) {
+top:
+  tail call void asm sideeffect "", "~{xmm0},~{xmm1},~{xmm2},~{xmm3},~{dirflag},~{fpsr},~{flags}"()
+  tail call void asm sideeffect "", "~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{dirflag},~{fpsr},~{flags}"()
+  %tmp1 = sitofp i32 %arg to float
+  ret float %tmp1
+;CHECK-LABEL:@only_xmm0_7
+;CHECK: vcvtsi2ssl {{.*}}, {{%xmm[0-7]+}}, {{%xmm[0-7]+}}
+}