radv: add a workaround for Monster Hunter World and LLVM 7&8

The load/store optimizer pass doesn't handle WaW hazards correctly
and this is the root cause of the reflection issue with Monster
Hunter World. AFAIK, it's the only game that are affected by this
issue.

This is fixed with LLVM r361008, but we need a workaround for older
LLVM versions unfortunately.

Cc: "19.0" "19.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/common/ac_llvm_util.c b/src/amd/common/ac_llvm_util.c
index 6944686..6063411 100644 (file)
--- a/src/amd/common/ac_llvm_util.c
+++ b/src/amd/common/ac_llvm_util.c
@@ -151,13 +151,14 @@ static LLVMTargetMachineRef ac_create_target_machine(enum radeon_family family,
        LLVMTargetRef target = ac_get_llvm_target(triple);
 
        snprintf(features, sizeof(features),
-                "+DumpCode,-fp32-denormals,+fp64-denormals%s%s%s%s%s",
+                "+DumpCode,-fp32-denormals,+fp64-denormals%s%s%s%s%s%s",
                 HAVE_LLVM >= 0x0800 ? "" : ",+vgpr-spilling",
                 tm_options & AC_TM_SISCHED ? ",+si-scheduler" : "",
                 tm_options & AC_TM_FORCE_ENABLE_XNACK ? ",+xnack" : "",
                 tm_options & AC_TM_FORCE_DISABLE_XNACK ? ",-xnack" : "",
-                tm_options & AC_TM_PROMOTE_ALLOCA_TO_SCRATCH ? ",-promote-alloca" : "");
-       
+                tm_options & AC_TM_PROMOTE_ALLOCA_TO_SCRATCH ? ",-promote-alloca" : "",
+                tm_options & AC_TM_NO_LOAD_STORE_OPT ? ",-load-store-opt" : "");
+
        LLVMTargetMachineRef tm = LLVMCreateTargetMachine(
                                     target,
                                     triple,

diff --git a/src/amd/common/ac_llvm_util.h b/src/amd/common/ac_llvm_util.h
index 6d961c0..ca00540 100644 (file)
--- a/src/amd/common/ac_llvm_util.h
+++ b/src/amd/common/ac_llvm_util.h
@@ -65,6 +65,7 @@ enum ac_target_machine_options {
        AC_TM_CHECK_IR = (1 << 5),
        AC_TM_ENABLE_GLOBAL_ISEL = (1 << 6),
        AC_TM_CREATE_LOW_OPT = (1 << 7),
+       AC_TM_NO_LOAD_STORE_OPT = (1 << 8),
 };
 
 enum ac_float_mode {

diff --git a/src/amd/vulkan/radv_debug.h b/src/amd/vulkan/radv_debug.h
index 17a2f33..652a3b6 100644 (file)
--- a/src/amd/vulkan/radv_debug.h
+++ b/src/amd/vulkan/radv_debug.h
@@ -51,6 +51,7 @@ enum {
        RADV_DEBUG_CHECKIR           = 0x200000,
        RADV_DEBUG_NOTHREADLLVM      = 0x400000,
        RADV_DEBUG_NOBINNING         = 0x800000,
+       RADV_DEBUG_NO_LOAD_STORE_OPT = 0x1000000,
 };
 
 enum {

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index c0e317a..4203074 100644 (file)
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -464,6 +464,7 @@ static const struct debug_control radv_debug_options[] = {
        {"checkir", RADV_DEBUG_CHECKIR},
        {"nothreadllvm", RADV_DEBUG_NOTHREADLLVM},
        {"nobinning", RADV_DEBUG_NOBINNING},
+       {"noloadstoreopt", RADV_DEBUG_NO_LOAD_STORE_OPT},
        {NULL, 0}
 };
 
@@ -510,6 +511,13 @@ radv_handle_per_app_options(struct radv_instance *instance,
        } else if (!strcmp(name, "DOOM_VFR")) {
                /* Work around a Doom VFR game bug */
                instance->debug_flags |= RADV_DEBUG_NO_DYNAMIC_BOUNDS;
+       } else if (!strcmp(name, "MonsterHunterWorld.exe")) {
+               /* Workaround for a WaW hazard when LLVM moves/merges
+                * load/store memory operations.
+                * See https://reviews.llvm.org/D61313
+                */
+               if (HAVE_LLVM < 0x900)
+                       instance->debug_flags |= RADV_DEBUG_NO_LOAD_STORE_OPT;
        }
 }
 

diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
index dfa5015..c585bac 100644 (file)
--- a/src/amd/vulkan/radv_shader.c
+++ b/src/amd/vulkan/radv_shader.c
@@ -649,6 +649,8 @@ shader_variant_create(struct radv_device *device,
                tm_options |= AC_TM_SISCHED;
        if (options->check_ir)
                tm_options |= AC_TM_CHECK_IR;
+       if (device->instance->debug_flags & RADV_DEBUG_NO_LOAD_STORE_OPT)
+               tm_options |= AC_TM_NO_LOAD_STORE_OPT;
 
        thread_compiler = !(device->instance->debug_flags & RADV_DEBUG_NOTHREADLLVM);
        radv_init_llvm_once();