[llvm] 8073201 - [AArch64] Lower fptrunc/fpext from/to FP128t to/from FP16

[Adhemerval Zanella via llvm-commits]

Author: Adhemerval Zanella
Date: 2020-11-19T15:14:50-03:00
New Revision: 807320119fbb22b372996f89b3223c752f74081a

URL: https://github.com/llvm/llvm-project/commit/807320119fbb22b372996f89b3223c752f74081a
DIFF: https://github.com/llvm/llvm-project/commit/807320119fbb22b372996f89b3223c752f74081a.diff

LOG: [AArch64] Lower fptrunc/fpext from/to FP128t to/from FP16

The compiler-rt part which adds the emitted symbols is handled in
a subsequent patch.

Differential Revision: https://reviews.llvm.org/D91731

Added: 
    

Modified: 
    llvm/include/llvm/IR/RuntimeLibcalls.def
    llvm/lib/CodeGen/TargetLoweringBase.cpp
    llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    llvm/test/CodeGen/AArch64/arm64-fp128.ll

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/RuntimeLibcalls.def b/llvm/include/llvm/IR/RuntimeLibcalls.def
index 75eef02ec70e..301bb0494476 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.def
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.def
@@ -286,6 +286,7 @@ HANDLE_LIBCALL(FPEXT_F64_PPCF128, "__gcc_dtoq")
 HANDLE_LIBCALL(FPEXT_F80_F128, "__extendxftf2")
 HANDLE_LIBCALL(FPEXT_F64_F128, "__extenddftf2")
 HANDLE_LIBCALL(FPEXT_F32_F128, "__extendsftf2")
+HANDLE_LIBCALL(FPEXT_F16_F128, "__extendhftf2")
 HANDLE_LIBCALL(FPEXT_F32_F64, "__extendsfdf2")
 HANDLE_LIBCALL(FPEXT_F16_F32, "__gnu_h2f_ieee")
 HANDLE_LIBCALL(FPROUND_F32_F16, "__gnu_f2h_ieee")

diff  --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 89cd0584017b..8b44885237c2 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -224,6 +224,8 @@ RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
   if (OpVT == MVT::f16) {
     if (RetVT == MVT::f32)
       return FPEXT_F16_F32;
+    if (RetVT == MVT::f128)
+      return FPEXT_F16_F128;
   } else if (OpVT == MVT::f32) {
     if (RetVT == MVT::f64)
       return FPEXT_F32_F64;

diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 53be7a7edf7a..463580c1e788 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -417,8 +417,10 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
   setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i32, Custom);
   setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i64, Custom);
   setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i128, Custom);
+  setOperationAction(ISD::FP_ROUND, MVT::f16, Custom);
   setOperationAction(ISD::FP_ROUND, MVT::f32, Custom);
   setOperationAction(ISD::FP_ROUND, MVT::f64, Custom);
+  setOperationAction(ISD::STRICT_FP_ROUND, MVT::f16, Custom);
   setOperationAction(ISD::STRICT_FP_ROUND, MVT::f32, Custom);
   setOperationAction(ISD::STRICT_FP_ROUND, MVT::f64, Custom);
 

diff  --git a/llvm/test/CodeGen/AArch64/arm64-fp128.ll b/llvm/test/CodeGen/AArch64/arm64-fp128.ll
index ad5366320cdb..1374f468c414 100644
--- a/llvm/test/CodeGen/AArch64/arm64-fp128.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-fp128.ll
@@ -219,6 +219,7 @@ define void @test_select(i1 %cond, fp128 %lhs, fp128 %rhs) {
 ; CHECK: ret
 }
 
+ at varhalf = global half 0.0, align 2
 @varfloat = global float 0.0, align 4
 @vardouble = global double 0.0, align 8
 
@@ -227,6 +228,12 @@ define void @test_round() {
 
   %val = load fp128, fp128* @lhs, align 16
 
+  %half = fptrunc fp128 %val to half
+  store half %half, half* @varhalf, align 2
+; CHECK: ldr q0, [{{x[0-9]+}}, :lo12:lhs]
+; CHECK: bl __trunctfhf2
+; CHECK: str h0, [{{x[0-9]+}}, :lo12:varhalf]
+
   %float = fptrunc fp128 %val to float
   store float %float, float* @varfloat, align 4
 ; CHECK: bl __trunctfsf2
@@ -245,6 +252,13 @@ define void @test_extend() {
 
   %val = load fp128, fp128* @lhs, align 16
 
+  %half = load half, half* @varhalf
+  %fromhalf = fpext half %half to fp128
+  store volatile fp128 %fromhalf, fp128* @lhs, align 16
+; CHECK: ldr h0, [{{x[0-9]+}}, :lo12:varhalf]
+; CHECK: bl __extendhftf2
+; CHECK: str q0, [{{x[0-9]+}}, :lo12:lhs]
+
   %float = load float, float* @varfloat
   %fromfloat = fpext float %float to fp128
   store volatile fp128 %fromfloat, fp128* @lhs, align 16