[llvm] r290307 - AMDGPU: Implement isFMAFasterThanFMulAndFAdd for f16

[Matt Arsenault via llvm-commits]

Author: arsenm
Date: Wed Dec 21 21:21:48 2016
New Revision: 290307

URL: http://llvm.org/viewvc/llvm-project?rev=290307&view=rev
Log:
AMDGPU: Implement isFMAFasterThanFMulAndFAdd for f16

Modified:
    llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp
    llvm/trunk/test/CodeGen/AMDGPU/llvm.fmuladd.f16.ll

Modified: llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp?rev=290307&r1=290306&r2=290307&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp Wed Dec 21 21:21:48 2016
@@ -1847,6 +1847,8 @@ bool SITargetLowering::isFMAFasterThanFM
     return Subtarget->hasFP32Denormals() && Subtarget->hasFastFMAF32();
   case MVT::f64:
     return true;
+  case MVT::f16:
+    return Subtarget->has16BitInsts() && Subtarget->hasFP16Denormals();
   default:
     break;
   }

Modified: llvm/trunk/test/CodeGen/AMDGPU/llvm.fmuladd.f16.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/llvm.fmuladd.f16.ll?rev=290307&r1=290306&r2=290307&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/llvm.fmuladd.f16.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/llvm.fmuladd.f16.ll Wed Dec 21 21:21:48 2016
@@ -1,5 +1,7 @@
-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=SI %s
-; RUN: llc -march=amdgcn -mcpu=fiji -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=VI %s
+; RUN: llc -march=amdgcn -mattr=-fp16-denormals -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=SI -check-prefix=SI-FLUSH %s
+; RUN: llc -march=amdgcn -mcpu=fiji -mattr=-fp16-denormals -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=VI -check-prefix=VI-FLUSH %s
+; RUN: llc -march=amdgcn -mattr=+fp16-denormals -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=SI -check-prefix=SI-DENORM %s
+; RUN: llc -march=amdgcn -mcpu=fiji -mattr=+fp16-denormals -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=VI -check-prefix=VI-DENORM %s
 
 declare half @llvm.fmuladd.f16(half %a, half %b, half %c)
 declare <2 x half> @llvm.fmuladd.v2f16(<2 x half> %a, <2 x half> %b, <2 x half> %c)
@@ -14,8 +16,13 @@ declare <2 x half> @llvm.fmuladd.v2f16(<
 ; SI:  v_mac_f32_e32 v[[C_F32]], v[[B_F32]], v[[A_F32]]
 ; SI:  v_cvt_f16_f32_e32 v[[R_F16:[0-9]+]], v[[C_F32]]
 ; SI:  buffer_store_short v[[R_F16]]
-; VI:  v_mac_f16_e32 v[[C_F16]], v[[B_F16]], v[[A_F16]]
-; VI:  buffer_store_short v[[C_F16]]
+
+; VI-FLUSH: v_mac_f16_e32 v[[C_F16]], v[[B_F16]], v[[A_F16]]
+; VI-FLUSH: buffer_store_short v[[C_F16]]
+
+; VI-DENORM: v_fma_f16 [[RESULT:v[0-9]+]], v[[A_F16]], v[[B_F16]], v[[C_F16]]
+; VI-DENORM: buffer_store_short [[RESULT]]
+
 ; GCN: s_endpgm
 define void @fmuladd_f16(
     half addrspace(1)* %r,
@@ -39,8 +46,14 @@ define void @fmuladd_f16(
 ; SI:  v_mac_f32_e32 v[[C_F32]], v[[A_F32]], v[[B_F32]]
 ; SI:  v_cvt_f16_f32_e32 v[[R_F16:[0-9]+]], v[[C_F32]]
 ; SI:  buffer_store_short v[[R_F16]]
-; VI:  v_mac_f16_e32 v[[C_F16]], 0x4200, v[[B_F16]]
-; VI:  buffer_store_short v[[C_F16]]
+
+; VI-FLUSH: v_mac_f16_e32 v[[C_F16]], 0x4200, v[[B_F16]]
+; VI-FLUSH: buffer_store_short v[[C_F16]]
+
+; VI-DENORM: v_mov_b32_e32 [[KA:v[0-9]+]], 0x4200
+; VI-DENORM: v_fma_f16 [[RESULT:v[0-9]+]], [[KA]], v[[B_F16]], v[[C_F16]]
+; VI-DENORM: buffer_store_short [[RESULT]]
+
 ; GCN: s_endpgm
 define void @fmuladd_f16_imm_a(
     half addrspace(1)* %r,
@@ -62,8 +75,15 @@ define void @fmuladd_f16_imm_a(
 ; SI:  v_mac_f32_e32 v[[C_F32]], v[[B_F32]], v[[A_F32]]
 ; SI:  v_cvt_f16_f32_e32 v[[R_F16:[0-9]+]], v[[C_F32]]
 ; SI:  buffer_store_short v[[R_F16]]
-; VI:  v_mac_f16_e32 v[[C_F16]], 0x4200, v[[A_F16]]
-; VI:  buffer_store_short v[[C_F16]]
+
+; VI-FLUSH: v_mac_f16_e32 v[[C_F16]], 0x4200, v[[A_F16]]
+; VI-FLUSH: buffer_store_short v[[C_F16]]
+
+; VI-DENORM: v_mov_b32_e32 [[KA:v[0-9]+]], 0x4200
+; VI-DENORM: v_fma_f16 [[RESULT:v[0-9]+]], [[KA]], v[[A_F16]], v[[C_F16]]
+; VI-DENORM buffer_store_short [[RESULT]]
+
+
 ; GCN: s_endpgm
 define void @fmuladd_f16_imm_b(
     half addrspace(1)* %r,
@@ -95,10 +115,19 @@ define void @fmuladd_f16_imm_b(
 ; SI:  v_cvt_f16_f32_e32 v[[R_F16_1:[0-9]+]], v[[C_F32_1]]
 ; SI:  v_and_b32_e32 v[[R_F16_LO:[0-9]+]], 0xffff, v[[R_F16_0]]
 ; SI:  v_lshlrev_b32_e32 v[[R_F16_HI:[0-9]+]], 16, v[[R_F16_1]]
-; VI:  v_mac_f16_e32 v[[C_V2_F16]], v[[B_V2_F16]], v[[A_V2_F16]]
-; VI:  v_mac_f16_e32 v[[C_F16_1]], v[[B_F16_1]], v[[A_F16_1]]
-; VI:  v_and_b32_e32 v[[R_F16_LO:[0-9]+]], 0xffff, v[[C_V2_F16]]
-; VI:  v_lshlrev_b32_e32 v[[R_F16_HI:[0-9]+]], 16, v[[C_F16_1]]
+
+
+; FIXME: and should be unnecessary
+; VI-FLUSH: v_mac_f16_e32 v[[C_V2_F16]], v[[B_V2_F16]], v[[A_V2_F16]]
+; VI-FLUSH: v_mac_f16_e32 v[[C_F16_1]], v[[B_F16_1]], v[[A_F16_1]]
+; VI-FLUSH: v_and_b32_e32 v[[R_F16_LO:[0-9]+]], 0xffff, v[[C_V2_F16]]
+; VI-FLUSH: v_lshlrev_b32_e32 v[[R_F16_HI:[0-9]+]], 16, v[[C_F16_1]]
+
+; VI-DENORM-DAG: v_fma_f16 v[[RES0:[0-9]+]], v[[A_V2_F16]], v[[B_V2_F16]], v[[C_V2_F16]]
+; VI-DENORM-DAG: v_fma_f16 v[[RES1:[0-9]+]], v[[A_F16_1]], v[[B_F16_1]], v[[C_F16_1]]
+; VI-DENORM: v_and_b32_e32 v[[R_F16_LO:[0-9]+]], 0xffff, v[[RES0]]
+; VI-DENORM: v_lshlrev_b32_e32 v[[R_F16_HI:[0-9]+]], 16, v[[RES1]]
+
 ; GCN: v_or_b32_e32 v[[R_V2_F16:[0-9]+]], v[[R_F16_HI]], v[[R_F16_LO]]
 ; GCN: buffer_store_dword v[[R_V2_F16]]
 ; GCN: s_endpgm