[CUDA] Allow function overloads in CUDA based on host/device attributes.

The patch makes it possible to parse CUDA files that contain host/device
functions with identical signatures, but different attributes without
having to physically split source into host-only and device-only parts.

This change is needed in order to parse CUDA header files that have
a lot of name clashes with standard include files.

Gory details are in design doc here: https://goo.gl/EXnymm
Feel free to leave comments there or in this review thread.

This feature is controlled with CC1 option -fcuda-target-overloads
and is disabled by default.

Differential Revision: http://reviews.llvm.org/D12453

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@248295 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 214 insertions, 0 deletions

diff --git a/test/CodeGenCUDA/function-overload.cu b/test/CodeGenCUDA/function-overload.cu
new file mode 100644
index 0000000000..a12ef82773
--- /dev/null
+++ b/test/CodeGenCUDA/function-overload.cu
@@ -0,0 +1,214 @@
+// REQUIRES: x86-registered-target
+// REQUIRES: nvptx-registered-target
+
+// Make sure we handle target overloads correctly.
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu \
+// RUN:     -fcuda-target-overloads -emit-llvm -o - %s \
+// RUN:     | FileCheck -check-prefix=CHECK-BOTH -check-prefix=CHECK-HOST %s
+// RUN: %clang_cc1 -triple nvptx64-nvidia-cuda -fcuda-is-device \
+// RUN:     -fcuda-target-overloads -emit-llvm -o - %s \
+// RUN:     | FileCheck -check-prefix=CHECK-BOTH -check-prefix=CHECK-DEVICE %s
+
+// Check target overloads handling with disabled call target checks.
+// RUN: %clang_cc1 -DNOCHECKS -triple x86_64-unknown-linux-gnu -emit-llvm \
+// RUN:    -fcuda-disable-target-call-checks -fcuda-target-overloads -o - %s \
+// RUN:     | FileCheck -check-prefix=CHECK-BOTH -check-prefix=CHECK-HOST \
+// RUN:    -check-prefix=CHECK-BOTH-NC -check-prefix=CHECK-HOST-NC %s
+// RUN: %clang_cc1 -DNOCHECKS -triple nvptx64-nvidia-cuda -emit-llvm \
+// RUN:    -fcuda-disable-target-call-checks -fcuda-target-overloads \
+// RUN:    -fcuda-is-device -o - %s \
+// RUN:     | FileCheck -check-prefix=CHECK-BOTH -check-prefix=CHECK-DEVICE \
+// RUN:    -check-prefix=CHECK-BOTH-NC -check-prefix=CHECK-DEVICE-NC %s
+
+#include "Inputs/cuda.h"
+
+typedef int (*fp_t)(void);
+typedef void (*gp_t)(void);
+
+// CHECK-HOST: @hp = global i32 ()* @_Z1hv
+// CHECK-HOST: @chp = global i32 ()* @ch
+// CHECK-HOST: @dhp = global i32 ()* @_Z2dhv
+// CHECK-HOST: @cdhp = global i32 ()* @cdh
+// CHECK-HOST: @gp = global void ()* @_Z1gv
+
+// CHECK-BOTH-LABEL: define i32 @_Z2dhv()
+__device__ int dh(void) { return 1; }
+// CHECK-DEVICE: ret i32 1
+__host__ int dh(void) { return 2; }
+// CHECK-HOST:   ret i32 2
+
+// CHECK-BOTH-LABEL: define i32 @_Z2hdv()
+__host__ __device__ int hd(void) { return 3; }
+// CHECK-BOTH:   ret i32 3
+
+// CHECK-DEVICE-LABEL: define i32 @_Z1dv()
+__device__ int d(void) { return 8; }
+// CHECK-DEVICE:   ret i32 8
+
+// CHECK-HOST-LABEL: define i32 @_Z1hv()
+__host__ int h(void) { return 9; }
+// CHECK-HOST:   ret i32 9
+
+// CHECK-BOTH-LABEL: define void @_Z1gv()
+__global__ void g(void) {}
+// CHECK-BOTH:   ret void
+
+// mangled names of extern "C" __host__ __device__ functions clash
+// with those of their __host__/__device__ counterparts, so
+// overloading of extern "C" functions can only happen for __host__
+// and __device__ functions -- we never codegen them in the same
+// compilation and therefore mangled name conflict is not a problem.
+
+// CHECK-BOTH-LABEL: define i32 @cdh()
+extern "C" __device__ int cdh(void) {return 10;}
+// CHECK-DEVICE:   ret i32 10
+extern "C" __host__ int cdh(void) {return 11;}
+// CHECK-HOST:     ret i32 11
+
+// CHECK-DEVICE-LABEL: define i32 @cd()
+extern "C" __device__ int cd(void) {return 12;}
+// CHECK-DEVICE:   ret i32 12
+
+// CHECK-HOST-LABEL: define i32 @ch()
+extern "C" __host__ int ch(void) {return 13;}
+// CHECK-HOST:     ret i32 13
+
+// CHECK-BOTH-LABEL: define i32 @chd()
+extern "C" __host__ __device__ int chd(void) {return 14;}
+// CHECK-BOTH:     ret i32 14
+
+// CHECK-HOST-LABEL: define void @_Z5hostfv()
+__host__ void hostf(void) {
+#if defined (NOCHECKS)
+  fp_t dp = d;   // CHECK-HOST-NC: store {{.*}} @_Z1dv, {{.*}} %dp,
+  fp_t cdp = cd; // CHECK-HOST-NC: store {{.*}} @cd, {{.*}} %cdp,
+#endif
+  fp_t hp = h; // CHECK-HOST: store {{.*}} @_Z1hv, {{.*}} %hp,
+  fp_t chp = ch; // CHECK-HOST: store {{.*}} @ch, {{.*}} %chp,
+  fp_t dhp = dh; // CHECK-HOST: store {{.*}} @_Z2dhv, {{.*}} %dhp,
+  fp_t cdhp = cdh; // CHECK-HOST: store {{.*}} @cdh, {{.*}} %cdhp,
+  fp_t hdp = hd; // CHECK-HOST: store {{.*}} @_Z2hdv, {{.*}} %hdp,
+  fp_t chdp = chd; // CHECK-HOST: store {{.*}} @chd, {{.*}} %chdp,
+  gp_t gp = g; // CHECK-HOST: store {{.*}} @_Z1gv, {{.*}} %gp,
+
+#if defined (NOCHECKS)
+  d();     // CHECK-HOST-NC: call i32 @_Z1dv()
+  cd();    // CHECK-HOST-NC: call i32 @cd()
+#endif
+  h();     // CHECK-HOST: call i32 @_Z1hv()
+  ch();    // CHECK-HOST: call i32 @ch()
+  dh();    // CHECK-HOST: call i32 @_Z2dhv()
+  cdh();   // CHECK-HOST: call i32 @cdh()
+  g<<<0,0>>>();  // CHECK-HOST: call void @_Z1gv()
+}
+
+// CHECK-DEVICE-LABEL: define void @_Z7devicefv()
+__device__ void devicef(void) {
+  fp_t dp = d;   // CHECK-DEVICE: store {{.*}} @_Z1dv, {{.*}} %dp,
+  fp_t cdp = cd; // CHECK-DEVICE: store {{.*}} @cd, {{.*}} %cdp,
+#if defined (NOCHECKS)
+  fp_t hp = h; // CHECK-DEVICE-NC: store {{.*}} @_Z1hv, {{.*}} %hp,
+  fp_t chp = ch; // CHECK-DEVICE-NC: store {{.*}} @ch, {{.*}} %chp,
+#endif
+  fp_t dhp = dh; // CHECK-DEVICE: store {{.*}} @_Z2dhv, {{.*}} %dhp,
+  fp_t cdhp = cdh; // CHECK-DEVICE: store {{.*}} @cdh, {{.*}} %cdhp,
+  fp_t hdp = hd; // CHECK-DEVICE: store {{.*}} @_Z2hdv, {{.*}} %hdp,
+  fp_t chdp = chd; // CHECK-DEVICE: store {{.*}} @chd, {{.*}} %chdp,
+
+  d();     // CHECK-DEVICE: call i32 @_Z1dv()
+  cd();    // CHECK-DEVICE: call i32 @cd()
+#if defined (NOCHECKS)
+  h();     // CHECK-DEVICE-NC: call i32 @_Z1hv()
+  ch();    // CHECK-DEVICE-NC: call i32 @ch()
+#endif
+  dh();    // CHECK-DEVICE: call i32 @_Z2dhv()
+  cdh();   // CHECK-DEVICE: call i32 @cdh()
+}
+
+// CHECK-BOTH-LABEL: define void @_Z11hostdevicefv()
+__host__ __device__ void hostdevicef(void) {
+#if defined (NOCHECKS)
+  fp_t dp = d;   // CHECK-BOTH-NC: store {{.*}} @_Z1dv, {{.*}} %dp,
+  fp_t cdp = cd; // CHECK-BOTH-NC: store {{.*}} @cd, {{.*}} %cdp,
+  fp_t hp = h; // CHECK-BOTH-NC: store {{.*}} @_Z1hv, {{.*}} %hp,
+  fp_t chp = ch; // CHECK-BOTH-NC: store {{.*}} @ch, {{.*}} %chp,
+#endif
+  fp_t dhp = dh; // CHECK-BOTH: store {{.*}} @_Z2dhv, {{.*}} %dhp,
+  fp_t cdhp = cdh; // CHECK-BOTH: store {{.*}} @cdh, {{.*}} %cdhp,
+  fp_t hdp = hd; // CHECK-BOTH: store {{.*}} @_Z2hdv, {{.*}} %hdp,
+  fp_t chdp = chd; // CHECK-BOTH: store {{.*}} @chd, {{.*}} %chdp,
+#if defined (NOCHECKS) && !defined(__CUDA_ARCH__)
+  gp_t gp = g; // CHECK-HOST-NC: store {{.*}} @_Z1gv, {{.*}} %gp,
+#endif
+
+#if defined (NOCHECKS)
+  d();     // CHECK-BOTH-NC: call i32 @_Z1dv()
+  cd();    // CHECK-BOTH-NC: call i32 @cd()
+  h();     // CHECK-BOTH-NC: call i32 @_Z1hv()
+  ch();    // CHECK-BOTH-NC: call i32 @ch()
+#endif
+  dh();    // CHECK-BOTH: call i32 @_Z2dhv()
+  cdh();   // CHECK-BOTH: call i32 @cdh()
+#if defined (NOCHECKS) && !defined(__CUDA_ARCH__)
+  g<<<0,0>>>();  // CHECK-HOST-NC: call void @_Z1gv()
+#endif
+}
+
+// Test for address of overloaded function resolution in the global context.
+fp_t hp = h;
+fp_t chp = ch;
+fp_t dhp = dh;
+fp_t cdhp = cdh;
+gp_t gp = g;
+
+int x;
+// Check constructors/destructors for D/H functions
+struct s_cd_dh {
+  __host__ s_cd_dh() { x = 11; }
+  __device__ s_cd_dh() { x = 12; }
+  __host__ ~s_cd_dh() { x = 21; }
+  __device__ ~s_cd_dh() { x = 22; }
+};
+
+struct s_cd_hd {
+  __host__ __device__ s_cd_hd() { x = 31; }
+  __host__ __device__ ~s_cd_hd() { x = 32; }
+};
+
+// CHECK-BOTH: define void @_Z7wrapperv
+#if defined(__CUDA_ARCH__)
+__device__
+#else
+__host__
+#endif
+void wrapper() {
+  s_cd_dh scddh;
+  // CHECK-BOTH: call void @_ZN7s_cd_dhC1Ev(
+  s_cd_hd scdhd;
+  // CHECK-BOTH: call void @_ZN7s_cd_hdC1Ev
+
+  // CHECK-BOTH: call void @_ZN7s_cd_hdD1Ev(
+  // CHECK-BOTH: call void @_ZN7s_cd_dhD1Ev(
+}
+// CHECK-BOTH: ret void
+
+// Now it's time to check what's been generated for the methods we used.
+
+// CHECK-BOTH: define linkonce_odr void @_ZN7s_cd_dhC2Ev(
+// CHECK-HOST:   store i32 11,
+// CHECK-DEVICE: store i32 12,
+// CHECK-BOTH: ret void
+
+// CHECK-BOTH: define linkonce_odr void @_ZN7s_cd_hdC2Ev(
+// CHECK-BOTH:   store i32 31,
+// CHECK-BOTH: ret void
+
+// CHECK-BOTH: define linkonce_odr void @_ZN7s_cd_hdD2Ev(
+// CHECK-BOTH: store i32 32,
+// CHECK-BOTH: ret void
+
+// CHECK-BOTH: define linkonce_odr void @_ZN7s_cd_dhD2Ev(
+// CHECK-HOST:   store i32 21,
+// CHECK-DEVICE: store i32 22,
+// CHECK-BOTH: ret void
+