Model sqrtss as a binary operation with one source operand tied to the destination...

This is a continuation of r167064 ( http://llvm.org/viewvc/llvm-project?view=revision&revision=167064 ).
That patch started to fix PR14221 ( http://llvm.org/bugs/show_bug.cgi?id=14221 ), but it was not completed.

Differential Revision: http://reviews.llvm.org/D6330

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224624 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86InstrSSE.td b/lib/Target/X86/X86InstrSSE.td
index 6d98d95584e18d8af3c11d8eb147f1a7e98974b8..e66813fa1516f9758c1ad0f1bdaea934fb07f2ed 100644 (file)
--- a/lib/Target/X86/X86InstrSSE.td
+++ b/lib/Target/X86/X86InstrSSE.td
@@ -3536,57 +3536,10 @@ def SSE_RCPS : OpndItins<
 >;
 }
 
-/// sse1_fp_unop_s - SSE1 unops in scalar form.
-multiclass sse1_fp_unop_s<bits<8> opc, string OpcodeStr,
-                          SDNode OpNode, Intrinsic F32Int, OpndItins itins> {
-let Predicates = [HasAVX], hasSideEffects = 0 in {
-  def V#NAME#SSr : SSI<opc, MRMSrcReg, (outs FR32:$dst),
-                      (ins FR32:$src1, FR32:$src2),
-                      !strconcat("v", OpcodeStr,
-                                 "ss\t{$src2, $src1, $dst|$dst, $src1, $src2}"),
-                      []>, VEX_4V, VEX_LIG, Sched<[itins.Sched]>;
-  let mayLoad = 1 in {
-  def V#NAME#SSm : SSI<opc, MRMSrcMem, (outs FR32:$dst),
-                      (ins FR32:$src1,f32mem:$src2),
-                      !strconcat("v", OpcodeStr,
-                                 "ss\t{$src2, $src1, $dst|$dst, $src1, $src2}"),
-                      []>, VEX_4V, VEX_LIG,
-                   Sched<[itins.Sched.Folded, ReadAfterLd]>;
-  let isCodeGenOnly = 1 in
-  def V#NAME#SSm_Int : SSI<opc, MRMSrcMem, (outs VR128:$dst),
-                      (ins VR128:$src1, ssmem:$src2),
-                      !strconcat("v", OpcodeStr,
-                                 "ss\t{$src2, $src1, $dst|$dst, $src1, $src2}"),
-                      []>, VEX_4V, VEX_LIG,
-                      Sched<[itins.Sched.Folded, ReadAfterLd]>;
-  }
-}
-
-  def SSr : SSI<opc, MRMSrcReg, (outs FR32:$dst), (ins FR32:$src),
-                !strconcat(OpcodeStr, "ss\t{$src, $dst|$dst, $src}"),
-                [(set FR32:$dst, (OpNode FR32:$src))]>, Sched<[itins.Sched]>;
-  // For scalar unary operations, fold a load into the operation
-  // only in OptForSize mode. It eliminates an instruction, but it also
-  // eliminates a whole-register clobber (the load), so it introduces a
-  // partial register update condition.
-  def SSm : I<opc, MRMSrcMem, (outs FR32:$dst), (ins f32mem:$src),
-                !strconcat(OpcodeStr, "ss\t{$src, $dst|$dst, $src}"),
-                [(set FR32:$dst, (OpNode (load addr:$src)))], itins.rm>, XS,
-            Requires<[UseSSE1, OptForSize]>, Sched<[itins.Sched.Folded]>;
-let isCodeGenOnly = 1 in {
-  def SSr_Int : SSI<opc, MRMSrcReg, (outs VR128:$dst), (ins VR128:$src),
-                    !strconcat(OpcodeStr, "ss\t{$src, $dst|$dst, $src}"),
-                    [(set VR128:$dst, (F32Int VR128:$src))], itins.rr>,
-                Sched<[itins.Sched]>;
-  def SSm_Int : SSI<opc, MRMSrcMem, (outs VR128:$dst), (ins ssmem:$src),
-                    !strconcat(OpcodeStr, "ss\t{$src, $dst|$dst, $src}"),
-                    [(set VR128:$dst, (F32Int sse_load_f32:$src))], itins.rm>,
-                Sched<[itins.Sched.Folded]>;
-}
-}
-
-/// sse1_fp_unop_s_rw - SSE1 unops where vector form has a read-write operand.
-multiclass sse1_fp_unop_rw<bits<8> opc, string OpcodeStr, SDNode OpNode,
+/// sse1_fp_unop_s - SSE1 unops in scalar form
+/// For the non-AVX defs, we need $src1 to be tied to $dst because
+/// the HW instructions are 2 operand / destructive.
+multiclass sse1_fp_unop_s<bits<8> opc, string OpcodeStr, SDNode OpNode,
                            OpndItins itins> {
 let Predicates = [HasAVX], hasSideEffects = 0 in {
   def V#NAME#SSr : SSI<opc, MRMSrcReg, (outs FR32:$dst),
@@ -3795,20 +3748,19 @@ let Predicates = [HasAVX] in {
 }
 
 // Square root.
-defm SQRT  : sse1_fp_unop_s<0x51, "sqrt",  fsqrt, int_x86_sse_sqrt_ss,
-                            SSE_SQRTSS>,
+defm SQRT  : sse1_fp_unop_s<0x51, "sqrt", fsqrt, SSE_SQRTSS>,
              sse1_fp_unop_p<0x51, "sqrt", fsqrt, SSE_SQRTPS>,
-             sse2_fp_unop_s<0x51, "sqrt",  fsqrt, int_x86_sse2_sqrt_sd,
+             sse2_fp_unop_s<0x51, "sqrt", fsqrt, int_x86_sse2_sqrt_sd,
                             SSE_SQRTSD>,
              sse2_fp_unop_p<0x51, "sqrt", fsqrt, SSE_SQRTPD>;
 
 // Reciprocal approximations. Note that these typically require refinement
 // in order to obtain suitable precision.
-defm RSQRT : sse1_fp_unop_rw<0x52, "rsqrt", X86frsqrt, SSE_RSQRTSS>,
+defm RSQRT : sse1_fp_unop_s<0x52, "rsqrt", X86frsqrt, SSE_RSQRTSS>,
              sse1_fp_unop_p<0x52, "rsqrt", X86frsqrt, SSE_RSQRTPS>,
              sse1_fp_unop_p_int<0x52, "rsqrt", int_x86_sse_rsqrt_ps,
                                 int_x86_avx_rsqrt_ps_256, SSE_RSQRTPS>;
-defm RCP   : sse1_fp_unop_rw<0x53, "rcp", X86frcp, SSE_RCPS>,
+defm RCP   : sse1_fp_unop_s<0x53, "rcp", X86frcp, SSE_RCPS>,
              sse1_fp_unop_p<0x53, "rcp", X86frcp, SSE_RCPP>,
              sse1_fp_unop_p_int<0x53, "rcp", int_x86_sse_rcp_ps,
                                 int_x86_avx_rcp_ps_256, SSE_RCPP>;
@@ -3869,13 +3821,15 @@ let Predicates = [HasAVX] in {
             (VRCPSSm_Int (v4f32 (IMPLICIT_DEF)), sse_load_f32:$src)>;
 }
 
-// Reciprocal approximations. Note that these typically require refinement
-// in order to obtain suitable precision.
+// These are unary operations, but they are modeled as having 2 source operands
+// because the high elements of the destination are unchanged in SSE.
 let Predicates = [UseSSE1] in {
   def : Pat<(int_x86_sse_rsqrt_ss VR128:$src),
             (RSQRTSSr_Int VR128:$src, VR128:$src)>;
   def : Pat<(int_x86_sse_rcp_ss VR128:$src),
             (RCPSSr_Int VR128:$src, VR128:$src)>;
+  def : Pat<(int_x86_sse_sqrt_ss VR128:$src),
+            (SQRTSSr_Int VR128:$src, VR128:$src)>;
 }
 
 // There is no f64 version of the reciprocal approximation instructions.

diff --git a/test/CodeGen/X86/sse_partial_update.ll b/test/CodeGen/X86/sse_partial_update.ll
index 2c16a554aebbd54b1448d440f20935629c927457..a88ab014641b8ab8a4707f020b0f678d06676861 100644 (file)
--- a/test/CodeGen/X86/sse_partial_update.ll
+++ b/test/CodeGen/X86/sse_partial_update.ll
@@ -5,11 +5,18 @@
 ; There is a mismatch between the intrinsic and the actual instruction.
 ; The actual instruction has a partial update of dest, while the intrinsic
 ; passes through the upper FP values. Here, we make sure the source and
-; destination of rsqrtss are the same.
-define void @t1(<4 x float> %a) nounwind uwtable ssp {
+; destination of each scalar unary op are the same.
+
+define void @rsqrtss(<4 x float> %a) nounwind uwtable ssp {
 entry:
-; CHECK-LABEL: t1:
+; CHECK-LABEL: rsqrtss:
 ; CHECK: rsqrtss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
   %0 = tail call <4 x float> @llvm.x86.sse.rsqrt.ss(<4 x float> %a) nounwind
   %a.addr.0.extract = extractelement <4 x float> %0, i32 0
   %conv = fpext float %a.addr.0.extract to double
@@ -21,10 +28,16 @@ entry:
 declare void @callee(double, double)
 declare <4 x float> @llvm.x86.sse.rsqrt.ss(<4 x float>) nounwind readnone
 
-define void @t2(<4 x float> %a) nounwind uwtable ssp {
+define void @rcpss(<4 x float> %a) nounwind uwtable ssp {
 entry:
-; CHECK-LABEL: t2:
+; CHECK-LABEL: rcpss:
 ; CHECK: rcpss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
   %0 = tail call <4 x float> @llvm.x86.sse.rcp.ss(<4 x float> %a) nounwind
   %a.addr.0.extract = extractelement <4 x float> %0, i32 0
   %conv = fpext float %a.addr.0.extract to double
@@ -34,3 +47,23 @@ entry:
   ret void
 }
 declare <4 x float> @llvm.x86.sse.rcp.ss(<4 x float>) nounwind readnone
+
+define void @sqrtss(<4 x float> %a) nounwind uwtable ssp {
+entry:
+; CHECK-LABEL: sqrtss:
+; CHECK: sqrtss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
+  %0 = tail call <4 x float> @llvm.x86.sse.sqrt.ss(<4 x float> %a) nounwind
+  %a.addr.0.extract = extractelement <4 x float> %0, i32 0
+  %conv = fpext float %a.addr.0.extract to double
+  %a.addr.4.extract = extractelement <4 x float> %0, i32 1
+  %conv3 = fpext float %a.addr.4.extract to double
+  tail call void @callee(double %conv, double %conv3) nounwind
+  ret void
+}
+declare <4 x float> @llvm.x86.sse.sqrt.ss(<4 x float>) nounwind readnone