Intercept calls to libm (#264)

* Intercept calls to libm

* Switch to using function names instead of symbols

* remove forgotten comment

crates/rustc_codegen_spirv/src/builder/builder_methods.rs

@@ -12,6 +12,7 @@ use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
 use rustc_codegen_ssa::mir::place::PlaceRef;
 use rustc_codegen_ssa::traits::{BuilderMethods, ConstMethods, LayoutTypeMethods, OverflowOp};
 use rustc_codegen_ssa::MemFlags;
+use rustc_middle::bug;
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
 use rustc_target::abi::{Abi, Align, Scalar, Size};
@@ -1973,11 +1974,26 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
         for (argument, argument_type) in args.iter().zip(argument_types) {
             assert_ty_eq!(self, argument.ty, argument_type);
         }
-        let args = args.iter().map(|arg| arg.def(self)).collect::<Vec<_>>();
+        let llfn_def = llfn.def(self);
-        self.emit()
+        let libm_intrinsic = self.libm_intrinsics.borrow().get(&llfn_def).cloned();
-            .function_call(result_type, None, llfn.def(self), args)
+        if let Some(libm_intrinsic) = libm_intrinsic {
-            .unwrap()
+            let result = self.call_libm_intrinsic(libm_intrinsic, result_type, args);
-            .with_type(result_type)
+            if result_type != result.ty {
+                bug!(
+                    "Mismatched libm result type for {:?}: expected {}, got {}",
+                    libm_intrinsic,
+                    self.debug_type(result_type),
+                    self.debug_type(result.ty),
+                );
+            }
+            result
+        } else {
+            let args = args.iter().map(|arg| arg.def(self)).collect::<Vec<_>>();
+            self.emit()
+                .function_call(result_type, None, llfn_def, args)
+                .unwrap()
+                .with_type(result_type)
+        }
     }
 
     fn zext(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value {

crates/rustc_codegen_spirv/src/builder/ext_inst.rs

@@ -53,33 +53,43 @@ impl ExtInst {
 }
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
-    pub fn gl_op(&mut self, op: GLOp, args: impl AsRef<[SpirvValue]>) -> SpirvValue {
+    pub fn gl_op(
+        &mut self,
+        op: GLOp,
+        result_type: Word,
+        args: impl AsRef<[SpirvValue]>,
+    ) -> SpirvValue {
         let args = args.as_ref();
         let glsl = self.ext_inst.borrow_mut().import_glsl(self);
         self.emit()
             .ext_inst(
-                args[0].ty,
+                result_type,
                 None,
                 glsl,
                 op as u32,
                 args.iter().map(|a| Operand::IdRef(a.def(self))),
             )
             .unwrap()
-            .with_type(args[0].ty)
+            .with_type(result_type)
     }
 
-    pub fn cl_op(&mut self, op: CLOp, args: impl AsRef<[SpirvValue]>) -> SpirvValue {
+    pub fn cl_op(
+        &mut self,
+        op: CLOp,
+        result_type: Word,
+        args: impl AsRef<[SpirvValue]>,
+    ) -> SpirvValue {
         let args = args.as_ref();
         let opencl = self.ext_inst.borrow_mut().import_opencl(self);
         self.emit()
             .ext_inst(
-                args[0].ty,
+                result_type,
                 None,
                 opencl,
                 op as u32,
                 args.iter().map(|a| Operand::IdRef(a.def(self))),
             )
             .unwrap()
-            .with_type(args[0].ty)
+            .with_type(result_type)
     }
 }

crates/rustc_codegen_spirv/src/builder/intrinsics.rs

@@ -1,6 +1,6 @@
 use super::Builder;
 use crate::abi::ConvSpirvType;
-use crate::builder_spirv::SpirvValueExt;
+use crate::builder_spirv::{SpirvValue, SpirvValueExt};
 use crate::codegen_cx::CodegenCx;
 use crate::spirv_type::SpirvType;
 use rspirv::spirv::{CLOp, GLOp};
@@ -30,6 +30,36 @@ fn int_type_width_signed(ty: Ty<'_>, cx: &CodegenCx<'_>) -> Option<(u64, bool)>
     }
 }
 
+impl Builder<'_, '_> {
+    pub fn copysign(&mut self, val: SpirvValue, sign: SpirvValue) -> SpirvValue {
+        let width = match self.lookup_type(val.ty) {
+            SpirvType::Float(width) => width,
+            other => bug!(
+                "copysign must have float argument, not {}",
+                other.debug(val.ty, self)
+            ),
+        };
+        let int_ty = SpirvType::Integer(width, false).def(self);
+        let (mask_sign, mask_value) = match width {
+            32 => (
+                self.constant_u32(1 << 31),
+                self.constant_u32(u32::max_value() >> 1),
+            ),
+            64 => (
+                self.constant_u64(1 << 63),
+                self.constant_u64(u64::max_value() >> 1),
+            ),
+            _ => bug!("copysign must have width 32 or 64, not {}", width),
+        };
+        let val_bits = self.bitcast(val, int_ty);
+        let sign_bits = self.bitcast(sign, int_ty);
+        let val_masked = self.and(val_bits, mask_value);
+        let sign_masked = self.and(sign_bits, mask_sign);
+        let result_bits = self.or(val_masked, sign_masked);
+        self.bitcast(result_bits, val.ty)
+    }
+}
+
 impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
     fn codegen_intrinsic_call(
         &mut self,
@@ -53,6 +83,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
         let arg_tys = sig.inputs();
         let name = self.tcx.item_name(def_id);
 
+        let ret_ty = self.layout_of(sig.output()).spirv_type(self);
         let result = PlaceRef::new_sized(llresult, fn_abi.ret.layout);
 
         let value = match name {
@@ -122,76 +153,88 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
             // TODO: Configure these to be ocl vs. gl ext instructions, etc.
             sym::sqrtf32 | sym::sqrtf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::sqrt, [args[0].immediate()])
+                    self.cl_op(CLOp::sqrt, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Sqrt, [args[0].immediate()])
+                    self.gl_op(GLOp::Sqrt, ret_ty, [args[0].immediate()])
                 }
             }
             sym::powif32 | sym::powif64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::pown, [args[0].immediate(), args[1].immediate()])
+                    self.cl_op(
+                        CLOp::pown,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 } else {
                     let float = self.sitofp(args[1].immediate(), args[0].immediate().ty);
-                    self.gl_op(GLOp::Pow, [args[0].immediate(), float])
+                    self.gl_op(GLOp::Pow, ret_ty, [args[0].immediate(), float])
                 }
             }
             sym::sinf32 | sym::sinf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::sin, [args[0].immediate()])
+                    self.cl_op(CLOp::sin, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Sin, [args[0].immediate()])
+                    self.gl_op(GLOp::Sin, ret_ty, [args[0].immediate()])
                 }
             }
             sym::cosf32 | sym::cosf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::cos, [args[0].immediate()])
+                    self.cl_op(CLOp::cos, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Cos, [args[0].immediate()])
+                    self.gl_op(GLOp::Cos, ret_ty, [args[0].immediate()])
                 }
             }
             sym::powf32 | sym::powf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::pow, [args[0].immediate(), args[1].immediate()])
+                    self.cl_op(
+                        CLOp::pow,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 } else {
-                    self.gl_op(GLOp::Pow, [args[0].immediate(), args[1].immediate()])
+                    self.gl_op(
+                        GLOp::Pow,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 }
             }
             sym::expf32 | sym::expf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::exp, [args[0].immediate()])
+                    self.cl_op(CLOp::exp, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Exp, [args[0].immediate()])
+                    self.gl_op(GLOp::Exp, ret_ty, [args[0].immediate()])
                 }
             }
             sym::exp2f32 | sym::exp2f64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::exp2, [args[0].immediate()])
+                    self.cl_op(CLOp::exp2, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Exp2, [args[0].immediate()])
+                    self.gl_op(GLOp::Exp2, ret_ty, [args[0].immediate()])
                 }
             }
             sym::logf32 | sym::logf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::log, [args[0].immediate()])
+                    self.cl_op(CLOp::log, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Log, [args[0].immediate()])
+                    self.gl_op(GLOp::Log, ret_ty, [args[0].immediate()])
                 }
             }
             sym::log2f32 | sym::log2f64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::log2, [args[0].immediate()])
+                    self.cl_op(CLOp::log2, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Log2, [args[0].immediate()])
+                    self.gl_op(GLOp::Log2, ret_ty, [args[0].immediate()])
                 }
             }
             sym::log10f32 | sym::log10f64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::log10, [args[0].immediate()])
+                    self.cl_op(CLOp::log10, ret_ty, [args[0].immediate()])
                 } else {
                     // spir-v glsl doesn't have log10, so,
                     // log10(x) == (1 / ln(10)) * ln(x)
                     let mul = self.constant_float(args[0].immediate().ty, 1.0 / 10.0f64.ln());
-                    let ln = self.gl_op(GLOp::Log, [args[0].immediate()]);
+                    let ln = self.gl_op(GLOp::Log, ret_ty, [args[0].immediate()]);
                     self.mul(mul, ln)
                 }
             }
@@ -199,6 +242,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
                 if self.kernel_mode {
                     self.cl_op(
                         CLOp::fma,
+                        ret_ty,
                         [
                             args[0].immediate(),
                             args[1].immediate(),
@@ -208,6 +252,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
                 } else {
                     self.gl_op(
                         GLOp::Fma,
+                        ret_ty,
                         [
                             args[0].immediate(),
                             args[1].immediate(),
@@ -218,92 +263,88 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
             }
             sym::fabsf32 | sym::fabsf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::fabs, [args[0].immediate()])
+                    self.cl_op(CLOp::fabs, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::FAbs, [args[0].immediate()])
+                    self.gl_op(GLOp::FAbs, ret_ty, [args[0].immediate()])
                 }
             }
             sym::minnumf32 | sym::minnumf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::fmin, [args[0].immediate(), args[1].immediate()])
+                    self.cl_op(
+                        CLOp::fmin,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 } else {
-                    self.gl_op(GLOp::FMin, [args[0].immediate(), args[1].immediate()])
+                    self.gl_op(
+                        GLOp::FMin,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 }
             }
             sym::maxnumf32 | sym::maxnumf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::fmax, [args[0].immediate(), args[1].immediate()])
+                    self.cl_op(
+                        CLOp::fmax,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 } else {
-                    self.gl_op(GLOp::FMax, [args[0].immediate(), args[1].immediate()])
+                    self.gl_op(
+                        GLOp::FMax,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 }
             }
             sym::copysignf32 | sym::copysignf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::copysign, [args[0].immediate(), args[1].immediate()])
+                    self.cl_op(
+                        CLOp::copysign,
+                        ret_ty,
+                        [args[0].immediate(), args[1].immediate()],
+                    )
                 } else {
                     let val = args[0].immediate();
                     let sign = args[1].immediate();
-                    let width = match self.lookup_type(val.ty) {
+                    self.copysign(val, sign)
-                        SpirvType::Float(width) => width,
-                        other => bug!(
-                            "copysign must have float argument, not {}",
-                            other.debug(val.ty, self)
-                        ),
-                    };
-                    let int_ty = SpirvType::Integer(width, false).def(self);
-                    let (mask_sign, mask_value) = match width {
-                        32 => (
-                            self.constant_u32(1 << 31),
-                            self.constant_u32(u32::max_value() >> 1),
-                        ),
-                        64 => (
-                            self.constant_u64(1 << 63),
-                            self.constant_u64(u64::max_value() >> 1),
-                        ),
-                        _ => bug!("copysign must have width 32 or 64, not {}", width),
-                    };
-                    let val_bits = self.bitcast(val, int_ty);
-                    let sign_bits = self.bitcast(sign, int_ty);
-                    let val_masked = self.and(val_bits, mask_value);
-                    let sign_masked = self.and(sign_bits, mask_sign);
-                    let result_bits = self.or(val_masked, sign_masked);
-                    self.bitcast(result_bits, val.ty)
                 }
             }
             sym::floorf32 | sym::floorf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::floor, [args[0].immediate()])
+                    self.cl_op(CLOp::floor, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Floor, [args[0].immediate()])
+                    self.gl_op(GLOp::Floor, ret_ty, [args[0].immediate()])
                 }
             }
             sym::ceilf32 | sym::ceilf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::ceil, [args[0].immediate()])
+                    self.cl_op(CLOp::ceil, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Ceil, [args[0].immediate()])
+                    self.gl_op(GLOp::Ceil, ret_ty, [args[0].immediate()])
                 }
             }
             sym::truncf32 | sym::truncf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::trunc, [args[0].immediate()])
+                    self.cl_op(CLOp::trunc, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Trunc, [args[0].immediate()])
+                    self.gl_op(GLOp::Trunc, ret_ty, [args[0].immediate()])
                 }
             }
             // TODO: Correctness of all these rounds
             sym::rintf32 | sym::rintf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::rint, [args[0].immediate()])
+                    self.cl_op(CLOp::rint, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Round, [args[0].immediate()])
+                    self.gl_op(GLOp::Round, ret_ty, [args[0].immediate()])
                 }
             }
             sym::nearbyintf32 | sym::nearbyintf64 | sym::roundf32 | sym::roundf64 => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::round, [args[0].immediate()])
+                    self.cl_op(CLOp::round, ret_ty, [args[0].immediate()])
                 } else {
-                    self.gl_op(GLOp::Round, [args[0].immediate()])
+                    self.gl_op(GLOp::Round, ret_ty, [args[0].immediate()])
                 }
             }
 
@@ -317,7 +358,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
             // TODO: Do we want to manually implement these instead of using intel instructions?
             sym::ctlz | sym::ctlz_nonzero => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::clz, [args[0].immediate()])
+                    self.cl_op(CLOp::clz, ret_ty, [args[0].immediate()])
                 } else {
                     self.ext_inst
                         .borrow_mut()
@@ -334,7 +375,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
             }
             sym::cttz | sym::cttz_nonzero => {
                 if self.kernel_mode {
-                    self.cl_op(CLOp::ctz, [args[0].immediate()])
+                    self.cl_op(CLOp::ctz, ret_ty, [args[0].immediate()])
                 } else {
                     self.emit()
                         .u_count_trailing_zeros_intel(

crates/rustc_codegen_spirv/src/builder/libm_intrinsics.rs

@@ -0,0 +1,351 @@
+use super::Builder;
+use crate::builder_spirv::{SpirvValue, SpirvValueExt};
+use rspirv::spirv::{GLOp, Word};
+use rustc_codegen_ssa::traits::BuilderMethods;
+
+#[derive(Copy, Clone, Debug)]
+pub enum LibmCustomIntrinsic {
+    CopySign,
+    Cbrt,
+    Erf,
+    Erfc,
+    Exp10,
+    Expm1,
+    Fdim,
+    Fmod,
+    Log10,
+    Hypot,
+    Ilogb,
+    J0,
+    Y0,
+    J1,
+    Y1,
+    Jn,
+    Yn,
+    Lgamma,
+    LgammaR,
+    Tgamma,
+    Log1p,
+    NextAfter,
+    Remainder,
+    RemQuo,
+    Scalbn,
+    SinCos,
+}
+
+#[derive(Copy, Clone, Debug)]
+pub enum LibmIntrinsic {
+    GLOp(GLOp),
+    Custom(LibmCustomIntrinsic),
+}
+
+pub const TABLE: &[(&str, LibmIntrinsic)] = &[
+    ("acos", LibmIntrinsic::GLOp(GLOp::Acos)),
+    ("acosf", LibmIntrinsic::GLOp(GLOp::Acos)),
+    ("acosh", LibmIntrinsic::GLOp(GLOp::Acosh)),
+    ("acoshf", LibmIntrinsic::GLOp(GLOp::Acosh)),
+    ("asin", LibmIntrinsic::GLOp(GLOp::Asin)),
+    ("asinf", LibmIntrinsic::GLOp(GLOp::Asin)),
+    ("asinh", LibmIntrinsic::GLOp(GLOp::Asinh)),
+    ("asinhf", LibmIntrinsic::GLOp(GLOp::Asinh)),
+    ("atan2", LibmIntrinsic::GLOp(GLOp::Atan2)),
+    ("atan2f", LibmIntrinsic::GLOp(GLOp::Atan2)),
+    ("atan", LibmIntrinsic::GLOp(GLOp::Atan)),
+    ("atanf", LibmIntrinsic::GLOp(GLOp::Atan)),
+    ("atanh", LibmIntrinsic::GLOp(GLOp::Atanh)),
+    ("atanhf", LibmIntrinsic::GLOp(GLOp::Atanh)),
+    ("cbrt", LibmIntrinsic::Custom(LibmCustomIntrinsic::Cbrt)),
+    ("cbrtf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Cbrt)),
+    ("ceil", LibmIntrinsic::GLOp(GLOp::Ceil)),
+    ("ceilf", LibmIntrinsic::GLOp(GLOp::Ceil)),
+    (
+        "copysign",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::CopySign),
+    ),
+    (
+        "copysignf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::CopySign),
+    ),
+    ("cos", LibmIntrinsic::GLOp(GLOp::Cos)),
+    ("cosf", LibmIntrinsic::GLOp(GLOp::Cos)),
+    ("cosh", LibmIntrinsic::GLOp(GLOp::Cosh)),
+    ("coshf", LibmIntrinsic::GLOp(GLOp::Cosh)),
+    ("erf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Erf)),
+    ("erff", LibmIntrinsic::Custom(LibmCustomIntrinsic::Erf)),
+    ("erfc", LibmIntrinsic::Custom(LibmCustomIntrinsic::Erfc)),
+    ("erfcf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Erfc)),
+    ("exp10", LibmIntrinsic::Custom(LibmCustomIntrinsic::Exp10)),
+    ("exp10f", LibmIntrinsic::Custom(LibmCustomIntrinsic::Exp10)),
+    ("exp2", LibmIntrinsic::GLOp(GLOp::Exp2)),
+    ("exp2f", LibmIntrinsic::GLOp(GLOp::Exp2)),
+    ("exp", LibmIntrinsic::GLOp(GLOp::Exp)),
+    ("expf", LibmIntrinsic::GLOp(GLOp::Exp)),
+    ("expm1", LibmIntrinsic::Custom(LibmCustomIntrinsic::Expm1)),
+    ("expm1f", LibmIntrinsic::Custom(LibmCustomIntrinsic::Expm1)),
+    ("fabs", LibmIntrinsic::GLOp(GLOp::FAbs)),
+    ("fabsf", LibmIntrinsic::GLOp(GLOp::FAbs)),
+    ("fdim", LibmIntrinsic::Custom(LibmCustomIntrinsic::Fdim)),
+    ("fdimf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Fdim)),
+    ("floor", LibmIntrinsic::GLOp(GLOp::Floor)),
+    ("floorf", LibmIntrinsic::GLOp(GLOp::Floor)),
+    ("fma", LibmIntrinsic::GLOp(GLOp::Fma)),
+    ("fmaf", LibmIntrinsic::GLOp(GLOp::Fma)),
+    ("fmax", LibmIntrinsic::GLOp(GLOp::FMax)),
+    ("fmaxf", LibmIntrinsic::GLOp(GLOp::FMax)),
+    ("fmin", LibmIntrinsic::GLOp(GLOp::FMin)),
+    ("fminf", LibmIntrinsic::GLOp(GLOp::FMin)),
+    ("fmod", LibmIntrinsic::Custom(LibmCustomIntrinsic::Fmod)),
+    ("fmodf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Fmod)),
+    ("frexp", LibmIntrinsic::GLOp(GLOp::FrexpStruct)),
+    ("frexpf", LibmIntrinsic::GLOp(GLOp::FrexpStruct)),
+    ("hypot", LibmIntrinsic::Custom(LibmCustomIntrinsic::Hypot)),
+    ("hypotf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Hypot)),
+    ("ilogb", LibmIntrinsic::Custom(LibmCustomIntrinsic::Ilogb)),
+    ("ilogbf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Ilogb)),
+    ("j0", LibmIntrinsic::Custom(LibmCustomIntrinsic::J0)),
+    ("j0f", LibmIntrinsic::Custom(LibmCustomIntrinsic::J0)),
+    ("y0", LibmIntrinsic::Custom(LibmCustomIntrinsic::Y0)),
+    ("y0f", LibmIntrinsic::Custom(LibmCustomIntrinsic::Y0)),
+    ("j1", LibmIntrinsic::Custom(LibmCustomIntrinsic::J1)),
+    ("j1f", LibmIntrinsic::Custom(LibmCustomIntrinsic::J1)),
+    ("y1", LibmIntrinsic::Custom(LibmCustomIntrinsic::Y1)),
+    ("y1f", LibmIntrinsic::Custom(LibmCustomIntrinsic::Y1)),
+    ("jn", LibmIntrinsic::Custom(LibmCustomIntrinsic::Jn)),
+    ("jnf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Jn)),
+    ("yn", LibmIntrinsic::Custom(LibmCustomIntrinsic::Yn)),
+    ("ynf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Yn)),
+    ("ldexp", LibmIntrinsic::GLOp(GLOp::Ldexp)),
+    ("ldexpf", LibmIntrinsic::GLOp(GLOp::Ldexp)),
+    ("lgamma", LibmIntrinsic::Custom(LibmCustomIntrinsic::Lgamma)),
+    (
+        "lgammaf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::Lgamma),
+    ),
+    (
+        "lgamma_r",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::LgammaR),
+    ),
+    (
+        "lgammaf_r",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::LgammaR),
+    ),
+    ("tgamma", LibmIntrinsic::Custom(LibmCustomIntrinsic::Tgamma)),
+    (
+        "tgammaf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::Tgamma),
+    ),
+    ("log10", LibmIntrinsic::Custom(LibmCustomIntrinsic::Log10)),
+    ("log10f", LibmIntrinsic::Custom(LibmCustomIntrinsic::Log10)),
+    ("log1p", LibmIntrinsic::Custom(LibmCustomIntrinsic::Log1p)),
+    ("log1pf", LibmIntrinsic::Custom(LibmCustomIntrinsic::Log1p)),
+    ("log2", LibmIntrinsic::GLOp(GLOp::Log2)),
+    ("log2f", LibmIntrinsic::GLOp(GLOp::Log2)),
+    ("log", LibmIntrinsic::GLOp(GLOp::Log)),
+    ("logf", LibmIntrinsic::GLOp(GLOp::Log)),
+    ("modf", LibmIntrinsic::GLOp(GLOp::ModfStruct)),
+    ("modff", LibmIntrinsic::GLOp(GLOp::ModfStruct)),
+    (
+        "nextafter",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::NextAfter),
+    ),
+    (
+        "nextafterf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::NextAfter),
+    ),
+    ("pow", LibmIntrinsic::GLOp(GLOp::Pow)),
+    ("powf", LibmIntrinsic::GLOp(GLOp::Pow)),
+    (
+        "remainder",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::Remainder),
+    ),
+    (
+        "remainderf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::Remainder),
+    ),
+    ("remquo", LibmIntrinsic::Custom(LibmCustomIntrinsic::RemQuo)),
+    (
+        "remquof",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::RemQuo),
+    ),
+    ("round", LibmIntrinsic::GLOp(GLOp::Round)),
+    ("roundf", LibmIntrinsic::GLOp(GLOp::Round)),
+    ("scalbn", LibmIntrinsic::Custom(LibmCustomIntrinsic::Scalbn)),
+    (
+        "scalbnf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::Scalbn),
+    ),
+    ("sin", LibmIntrinsic::GLOp(GLOp::Sin)),
+    ("sincos", LibmIntrinsic::Custom(LibmCustomIntrinsic::SinCos)),
+    (
+        "sincosf",
+        LibmIntrinsic::Custom(LibmCustomIntrinsic::SinCos),
+    ),
+    ("sinf", LibmIntrinsic::GLOp(GLOp::Sin)),
+    ("sinh", LibmIntrinsic::GLOp(GLOp::Sinh)),
+    ("sinhf", LibmIntrinsic::GLOp(GLOp::Sinh)),
+    ("sqrt", LibmIntrinsic::GLOp(GLOp::Sqrt)),
+    ("sqrtf", LibmIntrinsic::GLOp(GLOp::Sqrt)),
+    ("tan", LibmIntrinsic::GLOp(GLOp::Tan)),
+    ("tanf", LibmIntrinsic::GLOp(GLOp::Tan)),
+    ("tanh", LibmIntrinsic::GLOp(GLOp::Tanh)),
+    ("tanhf", LibmIntrinsic::GLOp(GLOp::Tanh)),
+    ("trunc", LibmIntrinsic::GLOp(GLOp::Trunc)),
+    ("truncf", LibmIntrinsic::GLOp(GLOp::Trunc)),
+];
+
+impl Builder<'_, '_> {
+    pub fn call_libm_intrinsic(
+        &mut self,
+        intrinsic: LibmIntrinsic,
+        result_type: Word,
+        args: &[SpirvValue],
+    ) -> SpirvValue {
+        match intrinsic {
+            LibmIntrinsic::GLOp(op) => self.gl_op(op, result_type, args),
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::SinCos) => {
+                assert_eq!(args.len(), 1);
+                let x = args[0];
+                let sin = self.gl_op(GLOp::Sin, x.ty, &[x]).def(self);
+                let cos = self.gl_op(GLOp::Cos, x.ty, &[x]).def(self);
+                self.emit()
+                    .composite_construct(result_type, None, [sin, cos].iter().copied())
+                    .unwrap()
+                    .with_type(result_type)
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Fmod) => {
+                assert_eq!(args.len(), 2);
+                self.emit()
+                    .f_mod(result_type, None, args[0].def(self), args[1].def(self))
+                    .unwrap()
+                    .with_type(result_type)
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::CopySign) => {
+                assert_eq!(args.len(), 2);
+                self.copysign(args[0], args[1])
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Cbrt) => {
+                assert_eq!(args.len(), 1);
+                self.gl_op(
+                    GLOp::Pow,
+                    result_type,
+                    &[args[0], self.constant_float(args[0].ty, 1.0 / 3.0)],
+                )
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Log10) => {
+                assert_eq!(args.len(), 1);
+                // log10(x) == (1 / ln(10)) * ln(x)
+                let mul = self.constant_float(args[0].ty, 1.0 / 10.0f64.ln());
+                let ln = self.gl_op(GLOp::Log, result_type, [args[0]]);
+                self.mul(mul, ln)
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Log1p) => {
+                assert_eq!(args.len(), 1);
+                let one = self.constant_float(args[0].ty, 1.0);
+                let add = self.add(args[0], one);
+                self.gl_op(GLOp::Log, result_type, &[add])
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Exp10) => {
+                assert_eq!(args.len(), 1);
+                // exp10(x) == exp(x * log(10));
+                let log10 = self.constant_float(args[0].ty, 10.0f64.ln());
+                let mul = self.mul(args[0], log10);
+                self.gl_op(GLOp::Exp, result_type, [mul])
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Expm1) => {
+                let exp = self.gl_op(GLOp::Exp, args[0].ty, &[args[0]]);
+                let one = self.constant_float(exp.ty, 1.0);
+                self.sub(exp, one)
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Erf) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Erf not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Erfc) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Erfc not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Fdim) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Fdim not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Hypot) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Hypot not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Ilogb) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Ilogb not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::J0) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "J0 not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Y0) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Y0 not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::J1) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "J1 not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Y1) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Y1 not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Jn) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Jn not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Yn) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Yn not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Lgamma) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Lgamma not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::LgammaR) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "LgammaR not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Tgamma) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Tgamma not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::NextAfter) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "NextAfter not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Remainder) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Remainder not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::RemQuo) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "RemQuo not supported yet");
+                undef
+            }
+            LibmIntrinsic::Custom(LibmCustomIntrinsic::Scalbn) => {
+                let undef = self.undef(result_type);
+                self.zombie(undef.def(self), "Scalbn not supported yet");
+                undef
+            }
+        }
+    }
+}

crates/rustc_codegen_spirv/src/builder/mod.rs

@@ -1,6 +1,7 @@
 mod builder_methods;
 mod ext_inst;
 mod intrinsics;
+pub mod libm_intrinsics;
 mod spirv_asm;
 
 pub use ext_inst::ExtInst;

crates/rustc_codegen_spirv/src/codegen_cx/declare.rs

@@ -10,7 +10,7 @@ use rustc_middle::bug;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::mir::mono::{Linkage, MonoItem, Visibility};
 use rustc_middle::ty::layout::FnAbiExt;
-use rustc_middle::ty::{Instance, ParamEnv, TypeFoldable};
+use rustc_middle::ty::{self, Instance, ParamEnv, TypeFoldable};
 use rustc_span::def_id::DefId;
 use rustc_span::Span;
 use rustc_target::abi::call::FnAbi;
@@ -125,6 +125,23 @@ impl<'tcx> CodegenCx<'tcx> {
             }
         }
 
+        let instance_def_id = instance.def_id();
+        if self.tcx.crate_name(instance_def_id.krate) == self.sym.libm {
+            let item_name = self.tcx.item_name(instance_def_id);
+            let intrinsic = self.sym.libm_intrinsics.get(&item_name);
+            if self.tcx.visibility(instance.def_id()) == ty::Visibility::Public {
+                match intrinsic {
+                    Some(&intrinsic) => {
+                        self.libm_intrinsics.borrow_mut().insert(fn_id, intrinsic);
+                    }
+                    None => self.tcx.sess.err(&format!(
+                        "missing libm intrinsic {}, which is {}",
+                        symbol_name, instance
+                    )),
+                }
+            }
+        }
+
         declared
     }
 

crates/rustc_codegen_spirv/src/codegen_cx/mod.rs

@@ -53,6 +53,7 @@ pub struct CodegenCx<'tcx> {
     pub instruction_table: InstructionTable,
     pub really_unsafe_ignore_bitcasts: RefCell<HashSet<SpirvValue>>,
     pub zombie_undefs_for_system_constant_pointers: RefCell<HashMap<Word, Word>>,
+    pub libm_intrinsics: RefCell<HashMap<Word, super::builder::libm_intrinsics::LibmIntrinsic>>,
     /// Some runtimes (e.g. intel-compute-runtime) disallow atomics on i8 and i16, even though it's allowed by the spec.
     /// This enables/disables them.
     pub i8_i16_atomics_allowed: bool,
@@ -104,6 +105,7 @@ impl<'tcx> CodegenCx<'tcx> {
             instruction_table: InstructionTable::new(),
             really_unsafe_ignore_bitcasts: Default::default(),
             zombie_undefs_for_system_constant_pointers: Default::default(),
+            libm_intrinsics: Default::default(),
             i8_i16_atomics_allowed: false,
         }
     }
@@ -168,6 +170,8 @@ impl<'tcx> CodegenCx<'tcx> {
             .contains_name(self.tcx.hir().krate_attrs(), sym::compiler_builtins)
             || self.tcx.crate_name(LOCAL_CRATE) == sym::core
             || self.tcx.crate_name(LOCAL_CRATE) == self.sym.spirv_std
+            || self.tcx.crate_name(LOCAL_CRATE) == self.sym.libm
+            || self.tcx.crate_name(LOCAL_CRATE) == self.sym.num_traits
     }
 
     pub fn finalize_module(self) -> Module {

crates/rustc_codegen_spirv/src/lib.rs

@@ -111,8 +111,7 @@ use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoader, MetadataLoaderDyn};
 use rustc_middle::mir::mono::{Linkage, MonoItem, Visibility};
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::query::Providers;
+use rustc_middle::ty::{self, query, DefIdTree, Instance, InstanceDef, TyCtxt};
-use rustc_middle::ty::{self, DefIdTree, Instance, InstanceDef, TyCtxt};
 use rustc_mir::util::write_mir_pretty;
 use rustc_session::config::{self, OptLevel, OutputFilenames, OutputType};
 use rustc_session::Session;
@@ -267,7 +266,7 @@ impl CodegenBackend for SpirvCodegenBackend {
         Box::new(SpirvMetadataLoader)
     }
 
-    fn provide(&self, providers: &mut Providers) {
+    fn provide(&self, providers: &mut query::Providers) {
         // This is a lil weird: so, we obviously don't support C ABIs at all. However, libcore does declare some extern
         // C functions:
         // https://github.com/rust-lang/rust/blob/5fae56971d8487088c0099c82c0a5ce1638b5f62/library/core/src/slice/cmp.rs#L119
@@ -290,7 +289,7 @@ impl CodegenBackend for SpirvCodegenBackend {
         };
     }
 
-    fn provide_extern(&self, providers: &mut Providers) {
+    fn provide_extern(&self, providers: &mut query::Providers) {
         // See comments in provide(), only this time we use the default *extern* provider.
         providers.fn_sig = |tcx, def_id| {
             let result = (rustc_interface::DEFAULT_EXTERN_QUERY_PROVIDERS.fn_sig)(tcx, def_id);

crates/rustc_codegen_spirv/src/symbols.rs

@@ -1,3 +1,4 @@
+use crate::builder::libm_intrinsics;
 use crate::codegen_cx::CodegenCx;
 use rspirv::spirv::{BuiltIn, ExecutionMode, ExecutionModel, StorageClass};
 use rustc_ast::ast::{AttrKind, Attribute, Lit, LitIntType, LitKind, NestedMetaItem};
@@ -15,6 +16,8 @@ pub struct Symbols {
 
     pub spirv: Symbol,
     pub spirv_std: Symbol,
+    pub libm: Symbol,
+    pub num_traits: Symbol,
     pub kernel: Symbol,
     pub simple: Symbol,
     pub vulkan: Symbol,
@@ -30,6 +33,7 @@ pub struct Symbols {
     really_unsafe_ignore_bitcasts: Symbol,
     attributes: HashMap<Symbol, SpirvAttribute>,
     execution_modes: HashMap<Symbol, (ExecutionMode, ExecutionModeExtraDim)>,
+    pub libm_intrinsics: HashMap<Symbol, libm_intrinsics::LibmIntrinsic>,
 }
 
 const BUILTINS: &[(&str, BuiltIn)] = {
@@ -322,22 +326,30 @@ impl Symbols {
             .chain(execution_models)
             .map(|(a, b)| (Symbol::intern(a), b));
         let mut attributes = HashMap::new();
-        attributes_iter.for_each(|(a, b)| {
+        for (a, b) in attributes_iter {
             let old = attributes.insert(a, b);
             // `.collect()` into a HashMap does not error on duplicates, so manually write out the
             // loop here to error on duplicates.
             assert!(old.is_none());
-        });
+        }
         let mut execution_modes = HashMap::new();
-        EXECUTION_MODES.iter().for_each(|(key, mode, dim)| {
+        for &(key, mode, dim) in EXECUTION_MODES {
-            let old = execution_modes.insert(Symbol::intern(key), (*mode, *dim));
+            let old = execution_modes.insert(Symbol::intern(key), (mode, dim));
             assert!(old.is_none());
-        });
+        }
+
+        let mut libm_intrinsics = HashMap::new();
+        for &(a, b) in libm_intrinsics::TABLE {
+            let old = libm_intrinsics.insert(Symbol::intern(a), b);
+            assert!(old.is_none());
+        }
         Self {
             fmt_decimal: Symbol::intern("fmt_decimal"),
 
             spirv: Symbol::intern("spirv"),
             spirv_std: Symbol::intern("spirv_std"),
+            libm: Symbol::intern("libm"),
+            num_traits: Symbol::intern("num_traits"),
             kernel: Symbol::intern("kernel"),
             simple: Symbol::intern("simple"),
             vulkan: Symbol::intern("vulkan"),
@@ -353,6 +365,7 @@ impl Symbols {
             really_unsafe_ignore_bitcasts: Symbol::intern("really_unsafe_ignore_bitcasts"),
             attributes,
             execution_modes,
+            libm_intrinsics,
         }
     }
 }