[flang] Add support for LSHIFT and RSHIFT intrinsics

[kkwli0]

Summary

This patch is to add support for LSHIFT and RSHIFT intrinsics which functionality is the same as the standard SHIFTL and SHIFTA intrinsics respectively. The change is to alias the two intrinsics to the standardized ones.

[klausler]

Needs a test.

[kkwli0]

@klausler Thanks for the quick review. Since these two intrinsics are made alias to the existing ones, I am not sure what is the suitable tests. The functionality part (e.g. code gen) is already covered by flang/test/Lower/Intrinsics/shift[lr].f90 and flang/test/Evalute/fold-shift.f90. Will the same tests with the name changed be good? Any advice is appreciated. Thanks.

[klausler]

In D138839#3954812, @kkwli0 wrote:

@klausler Thanks for the quick review. Since these two intrinsics are made alias to the existing ones, I am not sure what is the suitable tests. The functionality part (e.g. code gen) is already covered by flang/test/Lower/Intrinsics/shift[lr].f90 and flang/test/Evalute/fold-shift.f90. Will the same tests with the name changed be good? Any advice is appreciated. Thanks.

I'd try writing a test with -fdebug-unparse and FileCheck to confirm that references to the extension names have been replaced with the conforming names. If you grep the tests you'll find some others that do this.

[kkwli0]

In D138839#3954894, @klausler wrote:

In D138839#3954812, @kkwli0 wrote:

@klausler Thanks for the quick review. Since these two intrinsics are made alias to the existing ones, I am not sure what is the suitable tests. The functionality part (e.g. code gen) is already covered by flang/test/Lower/Intrinsics/shift[lr].f90 and flang/test/Evalute/fold-shift.f90. Will the same tests with the name changed be good? Any advice is appreciated. Thanks.

I'd try writing a test with -fdebug-unparse and FileCheck to confirm that references to the extension names have been replaced with the conforming names. If you grep the tests you'll find some others that do this.

Thanks for the advice.

[kkwli0]

Add tests

flang/docs/Intrinsics.md

 validates the argument types and deduces the return types.
 This phase currently supports all the intrinsic procedures listed above but the ones in the table below.
 
 | Intrinsic Category | Intrinsic Procedures Lacking Support |
 | --- | --- |
 | Coarray intrinsic functions | IMAGE_INDEX, COSHAPE |
 | Object characteristic inquiry functions | ALLOCATED, ASSOCIATED, EXTENDS_TYPE_OF, IS_CONTIGUOUS, PRESENT, RANK, SAME_TYPE, STORAGE_SIZE |
 | Type inquiry intrinsic functions | BIT_SIZE, DIGITS, EPSILON, HUGE, KIND, MAXEXPONENT, MINEXPONENT, NEW_LINE, PRECISION, RADIX, RANGE, TINY|
-| Non-standard intrinsic functions | AND, OR, XOR, LSHIFT, RSHIFT, SHIFT, ZEXT, IZEXT, COSD, SIND, TAND, ACOSD, ASIND, ATAND, ATAN2D, COMPL, DCMPLX, EQV, NEQV, INT8, JINT, JNINT, KNINT, QCMPLX, DREAL, DFLOAT, QEXT, QFLOAT, QREAL, DNUM, NUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN, SIZEOF, MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR, IARG, IARGC, NARGS, NUMARG, BADDRESS, IADDR, CACHESIZE, EOF, FP_CLASS, INT_PTR_KIND, ISNAN, MALLOC |
+| Non-standard intrinsic functions | AND, OR, XOR, SHIFT, ZEXT, IZEXT, COSD, SIND, TAND, ACOSD, ASIND, ATAND, ATAN2D, COMPL, DCMPLX, EQV, NEQV, INT8, JINT, JNINT, KNINT, QCMPLX, DREAL, DFLOAT, QEXT, QFLOAT, QREAL, DNUM, NUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN, SIZEOF, MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR, IARG, IARGC, NARGS, NUMARG, BADDRESS, IADDR, CACHESIZE, EOF, FP_CLASS, INT_PTR_KIND, ISNAN, MALLOC |
 | Intrinsic subroutines |MVBITS (elemental), CPU_TIME, DATE_AND_TIME, EVENT_QUERY, EXECUTE_COMMAND_LINE, GET_COMMAND, GET_COMMAND_ARGUMENT, GET_ENVIRONMENT_VARIABLE, MOVE_ALLOC, RANDOM_INIT, RANDOM_NUMBER, RANDOM_SEED, SYSTEM_CLOCK |
 | Atomic intrinsic subroutines | ATOMIC_ADD |
 | Collective intrinsic subroutines | CO_REDUCE |
 
 
 ### Intrinsic Function Folding
 Fortran Constant Expressions can contain references to a certain number of
 intrinsic functions (see Fortran 2018 standard section 10.1.12 for more details).

flang/lib/Evaluate/intrinsics.cpp

static const IntrinsicInterface genericIntrinsicFunction[]{
     {"__builtin_ieee_support_underflow_control",
         {{"x", AnyReal, Rank::elemental, Optionality::optional}},
         DefaultLogical},
 };
 
 // TODO: Coarray intrinsic functions
 //  IMAGE_INDEX, COSHAPE
 // TODO: Non-standard intrinsic functions
-//  LSHIFT, RSHIFT, SHIFT,
+//  SHIFT,
 //  COMPL, EQV, NEQV, INT8, JINT, JNINT, KNINT,
 //  QCMPLX, QEXT, QFLOAT, QREAL, DNUM,
 //  INUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN,
 //  MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR
 //  IARG, IARGC, NARGS, NUMARG, BADDRESS, IADDR, CACHESIZE,
 //  EOF, FP_CLASS, INT_PTR_KIND, MALLOC
 //  probably more (these are PGI + Intel, possibly incomplete)
 // TODO: Optionally warn on use of non-standard intrinsics:
 //  LOC, probably others
 // TODO: Optionally warn on operand promotion extension
 
 // Aliases for a few generic intrinsic functions for legacy
 // compatibility and builtins.
 static const std::pair<const char *, const char *> genericAlias[]{
     {"and", "iand"},
     {"imag", "aimag"},
+    {"lshift", "shiftl"},
     {"or", "ior"},
+    {"rshift", "shifta"},
     {"xor", "ieor"},
     {"__builtin_ieee_selected_real_kind", "selected_real_kind"},
 };
 
 // The following table contains the intrinsic functions listed in
 // Tables 16.2 and 16.3 in Fortran 2018.  The "unrestricted" functions
 // in Table 16.2 can be used as actual arguments, PROCEDURE() interfaces,
 // and procedure pointer targets.

flang/test/Semantics/lshift.f90

+! RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
+! Check that a call to LSHIFT is transformed to SHIFTL.
+
+subroutine test_default_integer()
+  integer :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,j)
+  k = lshift(16, 2)
+!CHECK: k=64_4
+end
+
+subroutine test_integer1()
+  integer(1) :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,int(j,kind=4))
+  print *, lshift(8_1, 2)
+!CHECK: PRINT *, 32_1
+end
+
+subroutine test_integer2()
+  integer(2) :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,int(j,kind=4))
+  print *, lshift(8_2, 2)
+!CHECK: PRINT *, 32_2
+end
+
+subroutine test_integer4()
+  integer(4) :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,j)
+  print *, lshift(8_4, 2)
+!CHECK: PRINT *, 32_4
+end
+
+subroutine test_integer8()
+  integer(8) :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,int(j,kind=4))
+  print *, lshift(-16_8, 2)
+!CHECK: PRINT *, -64_8
+end
+
+subroutine test_integer16()
+  integer(16) :: i, j, k
+  k = lshift(i, j)
+!CHECK: k=shiftl(i,int(j,kind=4))
+  print *, lshift(8_16, 2)
+!CHECK: PRINT *, 32_16
+end

flang/test/Semantics/rshift.f90

+! RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
+! Check that a call to RSHIFT is transformed to SHIFTA.
+
+subroutine test_default_integer()
+  integer :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,j)
+  k = rshift(16, 2)
+!CHECK: k=4_4
+end
+
+subroutine test_integer1()
+  integer(1) :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,int(j,kind=4))
+  print *, rshift(8_1, 2)
+!CHECK: PRINT *, 2_1
+end
+
+subroutine test_integer2()
+  integer(2) :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,int(j,kind=4))
+  print *, rshift(8_2, 2)
+!CHECK: PRINT *, 2_2
+end
+
+subroutine test_integer4()
+  integer(4) :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,j)
+  print *, rshift(8_4, 2)
+!CHECK: PRINT *, 2_4
+end
+
+subroutine test_integer8()
+  integer(8) :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,int(j,kind=4))
+  print *, rshift(-16_8, 2)
+!CHECK: PRINT *, -4_8
+end
+
+subroutine test_integer16()
+  integer(16) :: i, j, k
+  k = rshift(i, j)
+!CHECK: k=shifta(i,int(j,kind=4))
+  print *, rshift(8_16, 2)
+!CHECK: PRINT *, 2_16
+end