[OpenMP] Fix mangling for linear parameters with negative stride

[mikerice]

Summary

The 'n' character is used in place of '-' in the mangled name.

[ABataev]

LG

clang/lib/CodeGen/CGOpenMPRuntime.cpp

case Vector:
       break;
     }
     if (ParamAttr.HasVarStride)
       Out << "s" << ParamAttr.StrideOrArg;
     else if (ParamAttr.Kind == Linear || ParamAttr.Kind == LinearRef ||
              ParamAttr.Kind == LinearUVal || ParamAttr.Kind == LinearVal) {
       // Don't print the step value if it is not present or if it is
       // equal to 1.
-      if (ParamAttr.StrideOrArg != 1)
+      if (ParamAttr.StrideOrArg < 0)
+        Out << 'n' << -ParamAttr.StrideOrArg;
+      else if (ParamAttr.StrideOrArg != 1)
         Out << ParamAttr.StrideOrArg;
     }
 
     if (!!ParamAttr.Alignment)
       Out << 'a' << ParamAttr.Alignment;
   }
 
   return std::string(Out.str());

clang/test/OpenMP/declare_simd_codegen.cpp

#pragma omp declare simd simdlen(4) uniform(a)               \
                          linear(val(d):4) linear(val(e):a)   \
                          linear(uval(f):8) linear(uval(g):a) \
                          linear(ref(h):16) linear(ref(i):a)
 double Five(int a, short &b, short &c, short &d, short &e, short &f, short &g,
             short &h, short &i) {
   return a + int(b);
 }
 
+// Test negative strides
+#pragma omp declare simd simdlen(4) linear(a:-2) linear(b:-8) \
+                                    linear(uval(c):-4) linear(ref(d):-16) \
+                                    linear(e:-1) linear(f:-1) linear(g:0)
+double Six(int a, float *b, int &c, int *&d, char e, char *f, short g) {
+ return a + int(*b) + c + *d + e + *f + g;
+}
+
 // CHECK-DAG: define {{.+}}@_Z5add_1Pf(
 // CHECK-DAG: define {{.+}}@_Z1hIiEvPT_S1_S1_S1_(
 // CHECK-DAG: define {{.+}}@_Z1hIfEvPT_S1_S1_S1_(
 // CHECK-DAG: define {{.+}}@_ZN2VV3addEii(
 // CHECK-DAG: define {{.+}}@_ZN2VV6taddpfEPfRS0_(
 // CHECK-DAG: define {{.+}}@_ZN2VV4taddERA_iRi(
 // CHECK-DAG: define {{.+}}@_Z1fRA_i(
 // CHECK-DAG: define {{.+}}@_ZN3TVVILi16EfE6taddpfEPfRS1_(
 // CHECK-DAG: define {{.+}}@_ZN3TVVILi16EfE4taddEi(
 // CHECK-DAG: define {{.+}}@_Z3fooILi64EEvRAT__iRPf(
 // CHECK-DAG: define {{.+}}@_Z3bar2VVPf(
 // CHECK-DAG: define {{.+}}@_Z3baz2VVPi(
 // CHECK-DAG: define {{.+}}@_Z3bay2VVRPd(
 // CHECK-DAG: define {{.+}}@_Z3bax2VVPdi(
 // CHECK-DAG: define {{.+}}@_Z3fooPffi(
 // CHECK-DAG: define {{.+}}@_Z3food(
 // CHECK-DAG: declare {{.+}}@_Z5add_2Pf(
 // CHECK-DAG: define {{.+}}@_Z11constlineari(
 // CHECK-DAG: define {{.+}}@_Z3OneRiPiiS_S0_i
 // CHECK-DAG: define {{.+}}@_Z3TwoRiPiiS_S0_i
 // CHECK-DAG: define {{.+}}@_Z5ThreeRiS_
 // CHECK-DAG: define {{.+}}@_Z4FourRiS_
 // CHECK-DAG: define {{.+}}@_Z4FiveiRsS_S_S_S_S_S_S_
+// CHECK-DAG: define {{.+}}@_Z3SixiPfRiRPicPcs
 
 // CHECK-DAG: "_ZGVbM4l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVbN4l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVcM8l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVcN8l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVdM8l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVdN8l32__Z5add_1Pf"
 // CHECK-DAG: "_ZGVeM16l32__Z5add_1Pf"

 // CHECK-DAG: "_ZGVbM4L2l16l8Ll4l__Z3TwoRiPiiS_S0_i"
 // CHECK-DAG: "_ZGVbN4L2l16l8Ll4l__Z3TwoRiPiiS_S0_i"
 // CHECK-DAG: "_ZGVbM4U2U__Z5ThreeRiS_"
 // CHECK-DAG: "_ZGVbN4U2U__Z5ThreeRiS_"
 // CHECK-DAG: "_ZGVbM4R8R4__Z4FourRiS_"
 // CHECK-DAG: "_ZGVbN4R8R4__Z4FourRiS_"
 // CHECK-DAG: "_ZGVbM4uL2Ls0L4Ls0U8Us0R32Rs0__Z4FiveiRsS_S_S_S_S_S_S_"
 // CHECK-DAG: "_ZGVbN4uL2Ls0L4Ls0U8Us0R32Rs0__Z4FiveiRsS_S_S_S_S_S_S_"
+// CHECK-DAG: "_ZGVbM4ln2ln32Un4Rn128ln1ln1l0__Z3SixiPfRiRPicPcs"
+// CHECK-DAG: "_ZGVbN4ln2ln32Un4Rn128ln1ln1l0__Z3SixiPfRiRPicPcs"
 
 // CHECK-NOT: "_ZGV{{.+}}__Z1fRA_i
 
 #endif