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-rw-r--r--compiler/rustc_codegen_gcc/src/abi.rs39
-rw-r--r--compiler/rustc_codegen_gcc/src/archive.rs1
-rw-r--r--compiler/rustc_codegen_gcc/src/builder.rs174
-rw-r--r--compiler/rustc_codegen_gcc/src/common.rs4
-rw-r--r--compiler/rustc_codegen_gcc/src/consts.rs12
-rw-r--r--compiler/rustc_codegen_gcc/src/intrinsic/mod.rs20
-rw-r--r--compiler/rustc_codegen_gcc/src/lib.rs1
7 files changed, 205 insertions, 46 deletions
diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs
index 0ed3e1fbe..848c34211 100644
--- a/compiler/rustc_codegen_gcc/src/abi.rs
+++ b/compiler/rustc_codegen_gcc/src/abi.rs
@@ -107,45 +107,24 @@ pub trait FnAbiGccExt<'gcc, 'tcx> {
impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec<Type<'gcc>>, bool, FxHashSet<usize>) {
let mut on_stack_param_indices = FxHashSet::default();
- let args_capacity: usize = self.args.iter().map(|arg|
- if arg.pad.is_some() {
- 1
- }
- else {
- 0
- } +
- if let PassMode::Pair(_, _) = arg.mode {
- 2
- } else {
- 1
- }
- ).sum();
+
+ // This capacity calculation is approximate.
let mut argument_tys = Vec::with_capacity(
- if let PassMode::Indirect { .. } = self.ret.mode {
- 1
- }
- else {
- 0
- } + args_capacity,
+ self.args.len() + if let PassMode::Indirect { .. } = self.ret.mode { 1 } else { 0 }
);
let return_ty =
match self.ret.mode {
PassMode::Ignore => cx.type_void(),
PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_gcc_type(cx),
- PassMode::Cast(cast) => cast.gcc_type(cx),
+ PassMode::Cast(ref cast, _) => cast.gcc_type(cx),
PassMode::Indirect { .. } => {
argument_tys.push(cx.type_ptr_to(self.ret.memory_ty(cx)));
cx.type_void()
}
};
- for arg in &self.args {
- // add padding
- if let Some(ty) = arg.pad {
- argument_tys.push(ty.gcc_type(cx));
- }
-
+ for arg in self.args.iter() {
let arg_ty = match arg.mode {
PassMode::Ignore => continue,
PassMode::Direct(_) => arg.layout.immediate_gcc_type(cx),
@@ -157,7 +136,13 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
PassMode::Indirect { extra_attrs: Some(_), .. } => {
unimplemented!();
}
- PassMode::Cast(cast) => cast.gcc_type(cx),
+ PassMode::Cast(ref cast, pad_i32) => {
+ // add padding
+ if pad_i32 {
+ argument_tys.push(Reg::i32().gcc_type(cx));
+ }
+ cast.gcc_type(cx)
+ }
PassMode::Indirect { extra_attrs: None, on_stack: true, .. } => {
on_stack_param_indices.insert(argument_tys.len());
arg.memory_ty(cx)
diff --git a/compiler/rustc_codegen_gcc/src/archive.rs b/compiler/rustc_codegen_gcc/src/archive.rs
index f863abdcc..96c773101 100644
--- a/compiler/rustc_codegen_gcc/src/archive.rs
+++ b/compiler/rustc_codegen_gcc/src/archive.rs
@@ -45,6 +45,7 @@ impl ArchiveBuilderBuilder for ArArchiveBuilderBuilder {
_lib_name: &str,
_dll_imports: &[DllImport],
_tmpdir: &Path,
+ _is_direct_dependency: bool,
) -> PathBuf {
unimplemented!();
}
diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs
index 4d40dd099..6994eeb00 100644
--- a/compiler/rustc_codegen_gcc/src/builder.rs
+++ b/compiler/rustc_codegen_gcc/src/builder.rs
@@ -15,8 +15,11 @@ use gccjit::{
Type,
UnaryOp,
};
+use rustc_apfloat::{ieee, Float, Round, Status};
use rustc_codegen_ssa::MemFlags;
-use rustc_codegen_ssa::common::{AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope};
+use rustc_codegen_ssa::common::{
+ AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope, TypeKind,
+};
use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
use rustc_codegen_ssa::mir::place::PlaceRef;
use rustc_codegen_ssa::traits::{
@@ -31,6 +34,7 @@ use rustc_codegen_ssa::traits::{
StaticBuilderMethods,
};
use rustc_data_structures::fx::FxHashSet;
+use rustc_middle::bug;
use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
use rustc_middle::ty::layout::{FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
use rustc_span::Span;
@@ -1271,12 +1275,12 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
val
}
- fn fptoui_sat(&mut self, _val: RValue<'gcc>, _dest_ty: Type<'gcc>) -> Option<RValue<'gcc>> {
- None
+ fn fptoui_sat(&mut self, val: RValue<'gcc>, dest_ty: Type<'gcc>) -> RValue<'gcc> {
+ self.fptoint_sat(false, val, dest_ty)
}
- fn fptosi_sat(&mut self, _val: RValue<'gcc>, _dest_ty: Type<'gcc>) -> Option<RValue<'gcc>> {
- None
+ fn fptosi_sat(&mut self, val: RValue<'gcc>, dest_ty: Type<'gcc>) -> RValue<'gcc> {
+ self.fptoint_sat(true, val, dest_ty)
}
fn instrprof_increment(&mut self, _fn_name: RValue<'gcc>, _hash: RValue<'gcc>, _num_counters: RValue<'gcc>, _index: RValue<'gcc>) {
@@ -1285,6 +1289,166 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
}
impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
+ fn fptoint_sat(&mut self, signed: bool, val: RValue<'gcc>, dest_ty: Type<'gcc>) -> RValue<'gcc> {
+ let src_ty = self.cx.val_ty(val);
+ let (float_ty, int_ty) = if self.cx.type_kind(src_ty) == TypeKind::Vector {
+ assert_eq!(self.cx.vector_length(src_ty), self.cx.vector_length(dest_ty));
+ (self.cx.element_type(src_ty), self.cx.element_type(dest_ty))
+ } else {
+ (src_ty, dest_ty)
+ };
+
+ // FIXME(jistone): the following was originally the fallback SSA implementation, before LLVM 13
+ // added native `fptosi.sat` and `fptoui.sat` conversions, but it was used by GCC as well.
+ // Now that LLVM always relies on its own, the code has been moved to GCC, but the comments are
+ // still LLVM-specific. This should be updated, and use better GCC specifics if possible.
+
+ let int_width = self.cx.int_width(int_ty);
+ let float_width = self.cx.float_width(float_ty);
+ // LLVM's fpto[su]i returns undef when the input val is infinite, NaN, or does not fit into the
+ // destination integer type after rounding towards zero. This `undef` value can cause UB in
+ // safe code (see issue #10184), so we implement a saturating conversion on top of it:
+ // Semantically, the mathematical value of the input is rounded towards zero to the next
+ // mathematical integer, and then the result is clamped into the range of the destination
+ // integer type. Positive and negative infinity are mapped to the maximum and minimum value of
+ // the destination integer type. NaN is mapped to 0.
+ //
+ // Define f_min and f_max as the largest and smallest (finite) floats that are exactly equal to
+ // a value representable in int_ty.
+ // They are exactly equal to int_ty::{MIN,MAX} if float_ty has enough significand bits.
+ // Otherwise, int_ty::MAX must be rounded towards zero, as it is one less than a power of two.
+ // int_ty::MIN, however, is either zero or a negative power of two and is thus exactly
+ // representable. Note that this only works if float_ty's exponent range is sufficiently large.
+ // f16 or 256 bit integers would break this property. Right now the smallest float type is f32
+ // with exponents ranging up to 127, which is barely enough for i128::MIN = -2^127.
+ // On the other hand, f_max works even if int_ty::MAX is greater than float_ty::MAX. Because
+ // we're rounding towards zero, we just get float_ty::MAX (which is always an integer).
+ // This already happens today with u128::MAX = 2^128 - 1 > f32::MAX.
+ let int_max = |signed: bool, int_width: u64| -> u128 {
+ let shift_amount = 128 - int_width;
+ if signed { i128::MAX as u128 >> shift_amount } else { u128::MAX >> shift_amount }
+ };
+ let int_min = |signed: bool, int_width: u64| -> i128 {
+ if signed { i128::MIN >> (128 - int_width) } else { 0 }
+ };
+
+ let compute_clamp_bounds_single = |signed: bool, int_width: u64| -> (u128, u128) {
+ let rounded_min =
+ ieee::Single::from_i128_r(int_min(signed, int_width), Round::TowardZero);
+ assert_eq!(rounded_min.status, Status::OK);
+ let rounded_max =
+ ieee::Single::from_u128_r(int_max(signed, int_width), Round::TowardZero);
+ assert!(rounded_max.value.is_finite());
+ (rounded_min.value.to_bits(), rounded_max.value.to_bits())
+ };
+ let compute_clamp_bounds_double = |signed: bool, int_width: u64| -> (u128, u128) {
+ let rounded_min =
+ ieee::Double::from_i128_r(int_min(signed, int_width), Round::TowardZero);
+ assert_eq!(rounded_min.status, Status::OK);
+ let rounded_max =
+ ieee::Double::from_u128_r(int_max(signed, int_width), Round::TowardZero);
+ assert!(rounded_max.value.is_finite());
+ (rounded_min.value.to_bits(), rounded_max.value.to_bits())
+ };
+ // To implement saturation, we perform the following steps:
+ //
+ // 1. Cast val to an integer with fpto[su]i. This may result in undef.
+ // 2. Compare val to f_min and f_max, and use the comparison results to select:
+ // a) int_ty::MIN if val < f_min or val is NaN
+ // b) int_ty::MAX if val > f_max
+ // c) the result of fpto[su]i otherwise
+ // 3. If val is NaN, return 0.0, otherwise return the result of step 2.
+ //
+ // This avoids resulting undef because values in range [f_min, f_max] by definition fit into the
+ // destination type. It creates an undef temporary, but *producing* undef is not UB. Our use of
+ // undef does not introduce any non-determinism either.
+ // More importantly, the above procedure correctly implements saturating conversion.
+ // Proof (sketch):
+ // If val is NaN, 0 is returned by definition.
+ // Otherwise, val is finite or infinite and thus can be compared with f_min and f_max.
+ // This yields three cases to consider:
+ // (1) if val in [f_min, f_max], the result of fpto[su]i is returned, which agrees with
+ // saturating conversion for inputs in that range.
+ // (2) if val > f_max, then val is larger than int_ty::MAX. This holds even if f_max is rounded
+ // (i.e., if f_max < int_ty::MAX) because in those cases, nextUp(f_max) is already larger
+ // than int_ty::MAX. Because val is larger than int_ty::MAX, the return value of int_ty::MAX
+ // is correct.
+ // (3) if val < f_min, then val is smaller than int_ty::MIN. As shown earlier, f_min exactly equals
+ // int_ty::MIN and therefore the return value of int_ty::MIN is correct.
+ // QED.
+
+ let float_bits_to_llval = |bx: &mut Self, bits| {
+ let bits_llval = match float_width {
+ 32 => bx.cx().const_u32(bits as u32),
+ 64 => bx.cx().const_u64(bits as u64),
+ n => bug!("unsupported float width {}", n),
+ };
+ bx.bitcast(bits_llval, float_ty)
+ };
+ let (f_min, f_max) = match float_width {
+ 32 => compute_clamp_bounds_single(signed, int_width),
+ 64 => compute_clamp_bounds_double(signed, int_width),
+ n => bug!("unsupported float width {}", n),
+ };
+ let f_min = float_bits_to_llval(self, f_min);
+ let f_max = float_bits_to_llval(self, f_max);
+ let int_max = self.cx.const_uint_big(int_ty, int_max(signed, int_width));
+ let int_min = self.cx.const_uint_big(int_ty, int_min(signed, int_width) as u128);
+ let zero = self.cx.const_uint(int_ty, 0);
+
+ // If we're working with vectors, constants must be "splatted": the constant is duplicated
+ // into each lane of the vector. The algorithm stays the same, we are just using the
+ // same constant across all lanes.
+ let maybe_splat = |bx: &mut Self, val| {
+ if bx.cx().type_kind(dest_ty) == TypeKind::Vector {
+ bx.vector_splat(bx.vector_length(dest_ty), val)
+ } else {
+ val
+ }
+ };
+ let f_min = maybe_splat(self, f_min);
+ let f_max = maybe_splat(self, f_max);
+ let int_max = maybe_splat(self, int_max);
+ let int_min = maybe_splat(self, int_min);
+ let zero = maybe_splat(self, zero);
+
+ // Step 1 ...
+ let fptosui_result = if signed { self.fptosi(val, dest_ty) } else { self.fptoui(val, dest_ty) };
+ let less_or_nan = self.fcmp(RealPredicate::RealULT, val, f_min);
+ let greater = self.fcmp(RealPredicate::RealOGT, val, f_max);
+
+ // Step 2: We use two comparisons and two selects, with %s1 being the
+ // result:
+ // %less_or_nan = fcmp ult %val, %f_min
+ // %greater = fcmp olt %val, %f_max
+ // %s0 = select %less_or_nan, int_ty::MIN, %fptosi_result
+ // %s1 = select %greater, int_ty::MAX, %s0
+ // Note that %less_or_nan uses an *unordered* comparison. This
+ // comparison is true if the operands are not comparable (i.e., if val is
+ // NaN). The unordered comparison ensures that s1 becomes int_ty::MIN if
+ // val is NaN.
+ //
+ // Performance note: Unordered comparison can be lowered to a "flipped"
+ // comparison and a negation, and the negation can be merged into the
+ // select. Therefore, it not necessarily any more expensive than an
+ // ordered ("normal") comparison. Whether these optimizations will be
+ // performed is ultimately up to the backend, but at least x86 does
+ // perform them.
+ let s0 = self.select(less_or_nan, int_min, fptosui_result);
+ let s1 = self.select(greater, int_max, s0);
+
+ // Step 3: NaN replacement.
+ // For unsigned types, the above step already yielded int_ty::MIN == 0 if val is NaN.
+ // Therefore we only need to execute this step for signed integer types.
+ if signed {
+ // LLVM has no isNaN predicate, so we use (val == val) instead
+ let cmp = self.fcmp(RealPredicate::RealOEQ, val, val);
+ self.select(cmp, s1, zero)
+ } else {
+ s1
+ }
+ }
+
#[cfg(feature="master")]
pub fn shuffle_vector(&mut self, v1: RValue<'gcc>, v2: RValue<'gcc>, mask: RValue<'gcc>) -> RValue<'gcc> {
let struct_type = mask.get_type().is_struct().expect("mask of struct type");
diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs
index ccb6cbbc2..aa1c271c3 100644
--- a/compiler/rustc_codegen_gcc/src/common.rs
+++ b/compiler/rustc_codegen_gcc/src/common.rs
@@ -158,10 +158,6 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
None
}
- fn zst_to_backend(&self, _ty: Type<'gcc>) -> RValue<'gcc> {
- self.const_undef(self.type_ix(0))
- }
-
fn scalar_to_backend(&self, cv: Scalar, layout: abi::Scalar, ty: Type<'gcc>) -> RValue<'gcc> {
let bitsize = if layout.is_bool() { 1 } else { layout.size(self).bits() };
match cv {
diff --git a/compiler/rustc_codegen_gcc/src/consts.rs b/compiler/rustc_codegen_gcc/src/consts.rs
index c0b8d2181..356c03ee3 100644
--- a/compiler/rustc_codegen_gcc/src/consts.rs
+++ b/compiler/rustc_codegen_gcc/src/consts.rs
@@ -127,7 +127,7 @@ impl<'gcc, 'tcx> StaticMethods for CodegenCx<'gcc, 'tcx> {
//
// We could remove this hack whenever we decide to drop macOS 10.10 support.
if self.tcx.sess.target.options.is_like_osx {
- // The `inspect` method is okay here because we checked relocations, and
+ // The `inspect` method is okay here because we checked for provenance, and
// because we are doing this access to inspect the final interpreter state
// (not as part of the interpreter execution).
//
@@ -296,17 +296,17 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
pub fn const_alloc_to_gcc<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, alloc: ConstAllocation<'tcx>) -> RValue<'gcc> {
let alloc = alloc.inner();
- let mut llvals = Vec::with_capacity(alloc.relocations().len() + 1);
+ let mut llvals = Vec::with_capacity(alloc.provenance().len() + 1);
let dl = cx.data_layout();
let pointer_size = dl.pointer_size.bytes() as usize;
let mut next_offset = 0;
- for &(offset, alloc_id) in alloc.relocations().iter() {
+ for &(offset, alloc_id) in alloc.provenance().iter() {
let offset = offset.bytes();
assert_eq!(offset as usize as u64, offset);
let offset = offset as usize;
if offset > next_offset {
- // This `inspect` is okay since we have checked that it is not within a relocation, it
+ // This `inspect` is okay since we have checked that it is not within a pointer with provenance, it
// is within the bounds of the allocation, and it doesn't affect interpreter execution
// (we inspect the result after interpreter execution). Any undef byte is replaced with
// some arbitrary byte value.
@@ -319,7 +319,7 @@ pub fn const_alloc_to_gcc<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, alloc: ConstAl
read_target_uint( dl.endian,
// This `inspect` is okay since it is within the bounds of the allocation, it doesn't
// affect interpreter execution (we inspect the result after interpreter execution),
- // and we properly interpret the relocation as a relocation pointer offset.
+ // and we properly interpret the provenance as a relocation pointer offset.
alloc.inspect_with_uninit_and_ptr_outside_interpreter(offset..(offset + pointer_size)),
)
.expect("const_alloc_to_llvm: could not read relocation pointer")
@@ -336,7 +336,7 @@ pub fn const_alloc_to_gcc<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, alloc: ConstAl
}
if alloc.len() >= next_offset {
let range = next_offset..alloc.len();
- // This `inspect` is okay since we have check that it is after all relocations, it is
+ // This `inspect` is okay since we have check that it is after all provenance, it is
// within the bounds of the allocation, and it doesn't affect interpreter execution (we
// inspect the result after interpreter execution). Any undef byte is replaced with some
// arbitrary byte value.
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
index 5fbdedac0..02cedd464 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -130,7 +130,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
sym::volatile_load | sym::unaligned_volatile_load => {
let tp_ty = substs.type_at(0);
let mut ptr = args[0].immediate();
- if let PassMode::Cast(ty) = fn_abi.ret.mode {
+ if let PassMode::Cast(ty, _) = &fn_abi.ret.mode {
ptr = self.pointercast(ptr, self.type_ptr_to(ty.gcc_type(self)));
}
let load = self.volatile_load(ptr.get_type(), ptr);
@@ -309,6 +309,18 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
return;
}
+ sym::ptr_mask => {
+ let usize_type = self.context.new_type::<usize>();
+ let void_ptr_type = self.context.new_type::<*const ()>();
+
+ let ptr = args[0].immediate();
+ let mask = args[1].immediate();
+
+ let addr = self.bitcast(ptr, usize_type);
+ let masked = self.and(addr, mask);
+ self.bitcast(masked, void_ptr_type)
+ },
+
_ if name_str.starts_with("simd_") => {
match generic_simd_intrinsic(self, name, callee_ty, args, ret_ty, llret_ty, span) {
Ok(llval) => llval,
@@ -320,7 +332,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
};
if !fn_abi.ret.is_ignore() {
- if let PassMode::Cast(ty) = fn_abi.ret.mode {
+ if let PassMode::Cast(ty, _) = &fn_abi.ret.mode {
let ptr_llty = self.type_ptr_to(ty.gcc_type(self));
let ptr = self.pointercast(result.llval, ptr_llty);
self.store(llval, ptr, result.align);
@@ -416,7 +428,7 @@ impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
else if self.is_unsized_indirect() {
bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
}
- else if let PassMode::Cast(cast) = self.mode {
+ else if let PassMode::Cast(ref cast, _) = self.mode {
// FIXME(eddyb): Figure out when the simpler Store is safe, clang
// uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}.
let can_store_through_cast_ptr = false;
@@ -481,7 +493,7 @@ impl<'gcc, 'tcx> ArgAbiExt<'gcc, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
PassMode::Indirect { extra_attrs: Some(_), .. } => {
OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst);
},
- PassMode::Direct(_) | PassMode::Indirect { extra_attrs: None, .. } | PassMode::Cast(_) => {
+ PassMode::Direct(_) | PassMode::Indirect { extra_attrs: None, .. } | PassMode::Cast(..) => {
let next_arg = next();
self.store(bx, next_arg, dst);
},
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index 8a206c036..223466fb9 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -19,6 +19,7 @@
#![warn(rust_2018_idioms)]
#![warn(unused_lifetimes)]
+extern crate rustc_apfloat;
extern crate rustc_ast;
extern crate rustc_codegen_ssa;
extern crate rustc_data_structures;