sepavloff created this revision.
sepavloff added reviewers: andrew.w.kaylor, kpn, craig.topper, RKSimon, asb,
hfinkel.
Herald added subscribers: cfe-commits, luismarques, apazos, sameer.abuasal,
pzheng, jdoerfert, s.egerton, lenary, Jim, jocewei, PkmX, the_o, brucehoult,
MartinMosbeck, rogfer01, edward-jones, zzheng, MaskRay, jrtc27, niosHD,
sabuasal, simoncook, johnrusso, rbar, hiraditya.
Herald added projects: clang, LLVM.
This change makes assorted correction related to the intrinsic
`llvm.flt.rounds`:
- Added documentation entry in LangRef,
- Attributes of the intrinsic changed to be in line with other functions
dependent of floating-point environment,
- The intrinsic now is lowered by default into function call rather than to a
constant.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D79322
Files:
clang/include/clang/Basic/Builtins.def
llvm/docs/LangRef.rst
llvm/include/llvm/IR/Intrinsics.td
llvm/include/llvm/IR/RuntimeLibcalls.def
llvm/lib/CodeGen/IntrinsicLowering.cpp
llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
llvm/test/CodeGen/MSP430/flt_rounds.ll
llvm/test/CodeGen/RISCV/flt-rounds.ll
Index: llvm/test/CodeGen/RISCV/flt-rounds.ll
===================================================================
--- llvm/test/CodeGen/RISCV/flt-rounds.ll
+++ llvm/test/CodeGen/RISCV/flt-rounds.ll
@@ -9,12 +9,20 @@
define i32 @test_flt_rounds() nounwind {
; RV32I-LABEL: test_flt_rounds:
; RV32I: # %bb.0:
-; RV32I-NEXT: addi a0, zero, 1
+; RV32I-NEXT: addi sp, sp, -16
+; RV32I-NEXT: sw ra, 12(sp)
+; RV32I-NEXT: call __flt_rounds
+; RV32I-NEXT: lw ra, 12(sp)
+; RV32I-NEXT: addi sp, sp, 16
; RV32I-NEXT: ret
;
; RV64I-LABEL: test_flt_rounds:
; RV64I: # %bb.0:
-; RV64I-NEXT: addi a0, zero, 1
+; RV64I-NEXT: addi sp, sp, -16
+; RV64I-NEXT: sd ra, 8(sp)
+; RV64I-NEXT: call __flt_rounds
+; RV64I-NEXT: ld ra, 8(sp)
+; RV64I-NEXT: addi sp, sp, 16
; RV64I-NEXT: ret
%1 = call i32 @llvm.flt.rounds()
ret i32 %1
Index: llvm/test/CodeGen/MSP430/flt_rounds.ll
===================================================================
--- llvm/test/CodeGen/MSP430/flt_rounds.ll
+++ llvm/test/CodeGen/MSP430/flt_rounds.ll
@@ -1,4 +1,4 @@
-; RUN: llc -verify-machineinstrs < %s -march=msp430
+; RUN: llc -verify-machineinstrs -march=msp430 < %s | FileCheck %s
define i16 @foo() {
entry:
@@ -8,3 +8,5 @@
}
declare i32 @llvm.flt.rounds() nounwind
+
+; CHECK: call #__flt_rounds
Index: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2814,10 +2814,16 @@
FA, Offset));
break;
}
- case ISD::FLT_ROUNDS_:
- Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
- Results.push_back(Node->getOperand(0));
+ case ISD::FLT_ROUNDS_: {
+ EVT RetVT = Node->getValueType(0);
+ TargetLowering::MakeLibCallOptions CallOptions;
+ std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
+ DAG, RTLIB::FLT_ROUNDS_, RetVT, None, CallOptions,
+ SDLoc(Node), Node->getOperand(0));
+ Results.push_back(Tmp.first);
+ Results.push_back(Tmp.second);
break;
+ }
case ISD::EH_RETURN:
case ISD::EH_LABEL:
case ISD::PREFETCH:
Index: llvm/lib/CodeGen/IntrinsicLowering.cpp
===================================================================
--- llvm/lib/CodeGen/IntrinsicLowering.cpp
+++ llvm/lib/CodeGen/IntrinsicLowering.cpp
@@ -426,10 +426,9 @@
break;
}
case Intrinsic::flt_rounds:
- // Lower to "round to the nearest"
- if (!CI->getType()->isVoidTy())
- CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
- break;
+ ReplaceCallWith("__flt_rounds", CI, CI->arg_begin(), CI->arg_end(),
+ Type::getInt32Ty(CI->getContext()));
+ break;
case Intrinsic::invariant_start:
case Intrinsic::lifetime_start:
// Discard region information.
Index: llvm/include/llvm/IR/RuntimeLibcalls.def
===================================================================
--- llvm/include/llvm/IR/RuntimeLibcalls.def
+++ llvm/include/llvm/IR/RuntimeLibcalls.def
@@ -548,6 +548,9 @@
// Return address
HANDLE_LIBCALL(RETURN_ADDRESS, nullptr)
+// Floating-point Environment
+HANDLE_LIBCALL(FLT_ROUNDS_, "__flt_rounds")
+
HANDLE_LIBCALL(UNKNOWN_LIBCALL, nullptr)
#undef HANDLE_LIBCALL
Index: llvm/include/llvm/IR/Intrinsics.td
===================================================================
--- llvm/include/llvm/IR/Intrinsics.td
+++ llvm/include/llvm/IR/Intrinsics.td
@@ -611,6 +611,14 @@
[IntrNoMem, IntrSpeculatable, IntrWillReturn, ImmArg<1>, ImmArg<2>, ImmArg<3>]>,
GCCBuiltin<"__builtin_object_size">;
+//===--------------- Access to Floating Point Environment -----------------===//
+//
+
+let IntrProperties = [IntrInaccessibleMemOnly, IntrWillReturn] in {
+ def int_flt_rounds : Intrinsic<[llvm_i32_ty], []>,
+ GCCBuiltin<"__builtin_flt_rounds">;
+}
+
//===--------------- Constrained Floating Point Intrinsics ----------------===//
//
@@ -1114,8 +1122,6 @@
///===-------------------------- Other Intrinsics --------------------------===//
//
-def int_flt_rounds : Intrinsic<[llvm_i32_ty]>,
- GCCBuiltin<"__builtin_flt_rounds">;
def int_trap : Intrinsic<[], [], [IntrNoReturn, IntrCold]>,
GCCBuiltin<"__builtin_trap">;
def int_debugtrap : Intrinsic<[]>,
Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -18251,6 +18251,44 @@
would and handles error conditions in the same way.
+Floating Point Environment Manipulation intrinsics
+--------------------------------------------------
+
+These functions read or write floating point environment, such as rounding
+mode or state of floating point exceptions. Altering the floating point
+environment requires special care. See :ref:`Floating Point Environment <floatenv>`.
+
+'``llvm.flt.rounds``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+ declare i32 @llvm.flt.rounds()
+
+Overview:
+"""""""""
+
+The '``llvm.flt.rounds``' intrinsic reads current rounding mode.
+
+Semantics:
+""""""""""
+
+The '``llvm.flt.rounds``' intrinsic returns the current rounding mode.
+Encoding of the returned values is same as the result of ``FLT_ROUNDS``,
+specified by C standard:
+
+::
+
+ 0 - toward zero
+ 1 - to nearest, ties to even
+ 2 - toward positive infinity
+ 3 - toward negative infinity
+ 4 - to nearest, ties away from zero
+
+
General Intrinsics
------------------
Index: clang/include/clang/Basic/Builtins.def
===================================================================
--- clang/include/clang/Basic/Builtins.def
+++ clang/include/clang/Basic/Builtins.def
@@ -323,6 +323,9 @@
BUILTIN(__builtin_truncl, "LdLd", "Fnc")
BUILTIN(__builtin_truncf16, "hh", "Fnc")
+// Access to floating point environment
+BUILTIN(__builtin_flt_rounds, "i", "n")
+
// C99 complex builtins
BUILTIN(__builtin_cabs, "dXd", "Fne")
BUILTIN(__builtin_cabsf, "fXf", "Fne")
@@ -517,7 +520,6 @@
BUILTIN(__builtin_extract_return_addr, "v*v*", "n")
BUILTIN(__builtin_frame_address, "v*IUi", "n")
BUILTIN(__builtin___clear_cache, "vc*c*", "n")
-BUILTIN(__builtin_flt_rounds, "i", "nc")
BUILTIN(__builtin_setjmp, "iv**", "j")
BUILTIN(__builtin_longjmp, "vv**i", "r")
BUILTIN(__builtin_unwind_init, "v", "")
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