[ARM] Relax constraints on operands of VQxDMLxDH instructions

Summary:
According to a recently updated Armv8-M spec
(https://static.docs.arm.com/ddi0553/bh/DDI0553B_h_armv8m_arm.pdf) the
32-bit width versions of the following instructions:
* VQDMLADH
* VQDMLADHX
* VQRDMLADH
* VQRDMLADHX
* VQDMLSDH
* VQDMLSDHX
* VQRDMLSDH
* VQRDMLSDHX
are no longer unpredictable when their output register is the same as
one of the input registers.

This patch updates the assembler parser and the corresponding tests
and also removes @earlyclobber from the instruction constraints.

Reviewers: simon_tatham, ostannard, dmgreen, SjoerdMeijer, samparker

Reviewed By: simon_tatham

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64250

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365306 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMInstrMVE.td b/lib/Target/ARM/ARMInstrMVE.td
index e1882635c8b00ec981e32f4e7dae5105d6863aa2..06f8b18320c94e93f958b927f3c7f966609e98b6 100644 (file)
--- a/lib/Target/ARM/ARMInstrMVE.td
+++ b/lib/Target/ARM/ARMInstrMVE.td
@@ -2834,13 +2834,10 @@ class MVE_qDest_qSrc<string iname, string suffix, dag oops, dag iops,
 }
 
 class MVE_VQxDMLxDH<string iname, bit exch, bit round, bit subtract,
-                    string suffix, bits<2> size, bit earlyclobber,
-                    list<dag> pattern=[]>
+                    string suffix, bits<2> size, list<dag> pattern=[]>
   : MVE_qDest_qSrc<iname, suffix, (outs MQPR:$Qd),
                    (ins MQPR:$Qd_src, MQPR:$Qn, MQPR:$Qm), "$Qd, $Qn, $Qm",
-                   vpred_n,
-                   !if(earlyclobber, "@earlyclobber $Qd,", "") # "$Qd = $Qd_src",
-                   pattern> {
+                   vpred_n, "$Qd = $Qd_src", pattern> {
   bits<4> Qn;
 
   let Inst{28} = subtract;
@@ -2855,9 +2852,9 @@ class MVE_VQxDMLxDH<string iname, bit exch, bit round, bit subtract,
 
 multiclass MVE_VQxDMLxDH_multi<string iname, bit exch,
                                bit round, bit subtract> {
-  def s8  : MVE_VQxDMLxDH<iname, exch, round, subtract, "s8",  0b00, 0b0>;
-  def s16 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s16", 0b01, 0b0>;
-  def s32 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s32", 0b10, 0b1>;
+  def s8  : MVE_VQxDMLxDH<iname, exch, round, subtract, "s8",  0b00>;
+  def s16 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s16", 0b01>;
+  def s32 : MVE_VQxDMLxDH<iname, exch, round, subtract, "s32", 0b10>;
 }
 
 defm MVE_VQDMLADH   : MVE_VQxDMLxDH_multi<"vqdmladh",   0b0, 0b0, 0b0>;

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 3ff3af9dd58a56163b1fd0806973403e7b918a78..1da9452f1d22eb5a287445393b98c9bee518d4e4 100644 (file)
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -7865,15 +7865,7 @@ bool ARMAsmParser::validateInstruction(MCInst &Inst,
   case ARM::MVE_VMULLs32bh:
   case ARM::MVE_VMULLs32th:
   case ARM::MVE_VMULLu32bh:
-  case ARM::MVE_VMULLu32th:
-  case ARM::MVE_VQDMLADHs32:
-  case ARM::MVE_VQDMLADHXs32:
-  case ARM::MVE_VQRDMLADHs32:
-  case ARM::MVE_VQRDMLADHXs32:
-  case ARM::MVE_VQDMLSDHs32:
-  case ARM::MVE_VQDMLSDHXs32:
-  case ARM::MVE_VQRDMLSDHs32:
-  case ARM::MVE_VQRDMLSDHXs32: {
+  case ARM::MVE_VMULLu32th: {
     if (Operands[3]->getReg() == Operands[4]->getReg()) {
       return Error (Operands[3]->getStartLoc(),
                     "Qd register and Qn register can't be identical");

diff --git a/test/MC/ARM/mve-qdest-qsrc.s b/test/MC/ARM/mve-qdest-qsrc.s
index 851ca12d29dc273f8757486f2c8fcb6467be297b..410c69122bd5c071fe12d9d8a5ec39bc90d3069b 100644 (file)
--- a/test/MC/ARM/mve-qdest-qsrc.s
+++ b/test/MC/ARM/mve-qdest-qsrc.s
@@ -60,10 +60,12 @@ vqrdmladhx.s16 q0, q0, q1
 # CHECK-NOFP: vqrdmladhx.s32 q1, q0, q4  @ encoding: [0x20,0xee,0x09,0x3e]
 vqrdmladhx.s32 q1, q0, q4
 
-# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: Qd register and Qn register can't be identical
+# CHECK: vqrdmladhx.s32 q1, q1, q0  @ encoding: [0x22,0xee,0x01,0x3e]
+# CHECK-NOFP: vqrdmladhx.s32 q1, q1, q0  @ encoding: [0x22,0xee,0x01,0x3e]
 vqrdmladhx.s32 q1, q1, q0
 
-# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: Qd register and Qm register can't be identical
+# CHECK: vqrdmladhx.s32 q1, q0, q1  @ encoding: [0x20,0xee,0x03,0x3e]
+# CHECK-NOFP: vqrdmladhx.s32 q1, q0, q1  @ encoding: [0x20,0xee,0x03,0x3e]
 vqrdmladhx.s32 q1, q0, q1
 
 # CHECK: vqrdmladh.s8 q0, q6, q2  @ encoding: [0x0c,0xee,0x05,0x0e]
@@ -126,10 +128,12 @@ vqrdmlsdh.s16 q0, q7, q4
 # CHECK-NOFP: vqrdmlsdh.s32 q0, q6, q7  @ encoding: [0x2c,0xfe,0x0f,0x0e]
 vqrdmlsdh.s32 q0, q6, q7
 
-# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: Qd register and Qn register can't be identical
+# CHECK: vqrdmlsdh.s32 q0, q0, q7  @ encoding: [0x20,0xfe,0x0f,0x0e]
+# CHECK-NOFP: vqrdmlsdh.s32 q0, q0, q7  @ encoding: [0x20,0xfe,0x0f,0x0e]
 vqrdmlsdh.s32 q0, q0, q7
 
-# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: Qd register and Qm register can't be identical
+# CHECK: vqrdmlsdh.s32 q0, q6, q0  @ encoding: [0x2c,0xfe,0x01,0x0e]
+# CHECK-NOFP: vqrdmlsdh.s32 q0, q6, q0  @ encoding: [0x2c,0xfe,0x01,0x0e]
 vqrdmlsdh.s32 q0, q6, q0
 
 # CHECK: vcmul.f16 q0, q1, q2, #90 @ encoding: [0x32,0xee,0x05,0x0e]