[llvm] r370693 - [X86] Custom promote i32->f80 uint_to_fp on AVX512 64-bit targets.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Mon Sep  2 19:51:10 2019
New Revision: 370693

URL: http://llvm.org/viewvc/llvm-project?rev=370693&view=rev
Log:
[X86] Custom promote i32->f80 uint_to_fp on AVX512 64-bit targets.

Reuse the same code to promote all i32 uint_to_fp on 64-bit targets
to simplify the X86ISelLowering constructor.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/scalar-int-to-fp.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=370693&r1=370692&r2=370693&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Sep  2 19:51:10 2019
@@ -221,14 +221,7 @@ X86TargetLowering::X86TargetLowering(con
   setOperationAction(ISD::UINT_TO_FP       , MVT::i8   , Promote);
   setOperationAction(ISD::UINT_TO_FP       , MVT::i16  , Promote);
 
-  if (Subtarget.is64Bit()) {
-    if (!Subtarget.useSoftFloat() && Subtarget.hasAVX512())
-      // f32/f64 are legal, f80 is custom.
-      setOperationAction(ISD::UINT_TO_FP   , MVT::i32  , Custom);
-    else
-      setOperationAction(ISD::UINT_TO_FP   , MVT::i32  , Promote);
-    setOperationAction(ISD::UINT_TO_FP     , MVT::i64  , Custom);
-  } else if (!Subtarget.useSoftFloat()) {
+  if (!Subtarget.useSoftFloat()) {
     // We have an algorithm for SSE2->double, and we turn this into a
     // 64-bit FILD followed by conditional FADD for other targets.
     setOperationAction(ISD::UINT_TO_FP     , MVT::i64  , Custom);
@@ -18657,6 +18650,12 @@ SDValue X86TargetLowering::LowerUINT_TO_
     return Op;
   }
 
+  // Promote i32 to i64 and use a signed conversion on 64-bit targets.
+  if (SrcVT == MVT::i32 && Subtarget.is64Bit()) {
+    N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i64, N0);
+    return DAG.getNode(ISD::SINT_TO_FP, dl, DstVT, N0);
+  }
+
   if (SDValue V = LowerI64IntToFP_AVX512DQ(Op, DAG, Subtarget))
     return V;
 

Modified: llvm/trunk/test/CodeGen/X86/scalar-int-to-fp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/scalar-int-to-fp.ll?rev=370693&r1=370692&r2=370693&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/scalar-int-to-fp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/scalar-int-to-fp.ll Mon Sep  2 19:51:10 2019
@@ -230,15 +230,12 @@ define x86_fp80 @u32_to_x(i32 %a) nounwi
 ; AVX512_32-NEXT:    popl %ebp
 ; AVX512_32-NEXT:    retl
 ;
-; AVX512_64-LABEL: u32_to_x:
-; AVX512_64:       # %bb.0:
-; AVX512_64-NEXT:    vmovq {{.*#+}} xmm0 = mem[0],zero
-; AVX512_64-NEXT:    vmovd %edi, %xmm1
-; AVX512_64-NEXT:    vpor %xmm0, %xmm1, %xmm1
-; AVX512_64-NEXT:    vsubsd %xmm0, %xmm1, %xmm0
-; AVX512_64-NEXT:    vmovsd %xmm0, -{{[0-9]+}}(%rsp)
-; AVX512_64-NEXT:    fldl -{{[0-9]+}}(%rsp)
-; AVX512_64-NEXT:    retq
+; CHECK64-LABEL: u32_to_x:
+; CHECK64:       # %bb.0:
+; CHECK64-NEXT:    movl %edi, %eax
+; CHECK64-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
+; CHECK64-NEXT:    fildll -{{[0-9]+}}(%rsp)
+; CHECK64-NEXT:    retq
 ;
 ; SSE2_32-LABEL: u32_to_x:
 ; SSE2_32:       # %bb.0:
@@ -256,13 +253,6 @@ define x86_fp80 @u32_to_x(i32 %a) nounwi
 ; SSE2_32-NEXT:    popl %ebp
 ; SSE2_32-NEXT:    retl
 ;
-; SSE2_64-LABEL: u32_to_x:
-; SSE2_64:       # %bb.0:
-; SSE2_64-NEXT:    movl %edi, %eax
-; SSE2_64-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)
-; SSE2_64-NEXT:    fildll -{{[0-9]+}}(%rsp)
-; SSE2_64-NEXT:    retq
-;
 ; X87-LABEL: u32_to_x:
 ; X87:       # %bb.0:
 ; X87-NEXT:    pushl %ebp