[llvm] r335024 - If the arch is P9, we will select the DFLOADf32/DFLOADf64 pseudo instruction when we are loading a floating,

QingShan Zhang via llvm-commits llvm-commits at lists.llvm.org
Mon Jun 18 23:54:52 PDT 2018


Author: qshanz
Date: Mon Jun 18 23:54:51 2018
New Revision: 335024

URL: http://llvm.org/viewvc/llvm-project?rev=335024&view=rev
Log:
If the arch is P9, we will select the DFLOADf32/DFLOADf64 pseudo instruction when we are loading a floating,
and expand it post RA basing on the register pressure. However, we miss to do the add-imm peephole for these pseudo instruction.

Differential Revision: https://reviews.llvm.org/D47568
Reviewed By: Nemanjai


Added:
    llvm/trunk/test/CodeGen/PowerPC/toc-float.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
    llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
    llvm/trunk/test/CodeGen/PowerPC/mcm-12.ll

Modified: llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp?rev=335024&r1=335023&r2=335024&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp Mon Jun 18 23:54:51 2018
@@ -6044,28 +6044,37 @@ void PPCDAGToDAGISel::PeepholePPC64() {
 
     unsigned FirstOp;
     unsigned StorageOpcode = N->getMachineOpcode();
+    bool RequiresMod4Offset = false;
 
     switch (StorageOpcode) {
     default: continue;
 
+    case PPC::LWA:
+    case PPC::LD:
+    case PPC::DFLOADf64:
+    case PPC::DFLOADf32:
+      RequiresMod4Offset = true;
+      LLVM_FALLTHROUGH;
     case PPC::LBZ:
     case PPC::LBZ8:
-    case PPC::LD:
     case PPC::LFD:
     case PPC::LFS:
     case PPC::LHA:
     case PPC::LHA8:
     case PPC::LHZ:
     case PPC::LHZ8:
-    case PPC::LWA:
     case PPC::LWZ:
     case PPC::LWZ8:
       FirstOp = 0;
       break;
 
+    case PPC::STD:
+    case PPC::DFSTOREf64:
+    case PPC::DFSTOREf32:
+      RequiresMod4Offset = true;
+      LLVM_FALLTHROUGH;
     case PPC::STB:
     case PPC::STB8:
-    case PPC::STD:
     case PPC::STFD:
     case PPC::STFS:
     case PPC::STH:
@@ -6112,9 +6121,7 @@ void PPCDAGToDAGISel::PeepholePPC64() {
       // For these cases, the immediate may not be divisible by 4, in
       // which case the fold is illegal for DS-form instructions.  (The
       // other cases provide aligned addresses and are always safe.)
-      if ((StorageOpcode == PPC::LWA ||
-           StorageOpcode == PPC::LD  ||
-           StorageOpcode == PPC::STD) &&
+      if (RequiresMod4Offset &&
           (!isa<ConstantSDNode>(Base.getOperand(1)) ||
            Base.getConstantOperandVal(1) % 4 != 0))
         continue;
@@ -6176,8 +6183,7 @@ void PPCDAGToDAGISel::PeepholePPC64() {
       if (auto *C = dyn_cast<ConstantSDNode>(ImmOpnd)) {
         Offset += C->getSExtValue();
 
-        if ((StorageOpcode == PPC::LWA || StorageOpcode == PPC::LD ||
-             StorageOpcode == PPC::STD) && (Offset % 4) != 0)
+        if (RequiresMod4Offset && (Offset % 4) != 0)
           continue;
 
         if (!isInt<16>(Offset))
@@ -6209,8 +6215,7 @@ void PPCDAGToDAGISel::PeepholePPC64() {
         // We can't perform this optimization for data whose alignment
         // is insufficient for the instruction encoding.
         if (GV->getAlignment() < 4 &&
-            (StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
-             StorageOpcode == PPC::LWA || (Offset % 4) != 0)) {
+            (RequiresMod4Offset || (Offset % 4) != 0)) {
           LLVM_DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
           continue;
         }

Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp?rev=335024&r1=335023&r2=335024&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp Mon Jun 18 23:54:51 2018
@@ -2065,6 +2065,12 @@ bool PPCInstrInfo::expandVSXMemPseudo(Ma
     return true;
 }
 
+#ifndef NDEBUG
+static bool isAnImmediateOperand(const MachineOperand &MO) {
+  return MO.isCPI() || MO.isGlobal() || MO.isImm();
+}
+#endif
+
 bool PPCInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
   auto &MBB = *MI.getParent();
   auto DL = MI.getDebugLoc();
@@ -2087,7 +2093,8 @@ bool PPCInstrInfo::expandPostRAPseudo(Ma
   case PPC::DFSTOREf64: {
     assert(Subtarget.hasP9Vector() &&
            "Invalid D-Form Pseudo-ops on Pre-P9 target.");
-    assert(MI.getOperand(2).isReg() && MI.getOperand(1).isImm() &&
+    assert(MI.getOperand(2).isReg() &&
+           isAnImmediateOperand(MI.getOperand(1)) &&
            "D-form op must have register and immediate operands");
     return expandVSXMemPseudo(MI);
   }

Modified: llvm/trunk/test/CodeGen/PowerPC/mcm-12.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/mcm-12.ll?rev=335024&r1=335023&r2=335024&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/mcm-12.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/mcm-12.ll Mon Jun 18 23:54:51 2018
@@ -33,5 +33,4 @@ entry:
 ; CHECK-P9: .quad 4562098671269285104
 ; CHECK-P9-LABEL: test_double_const:
 ; CHECK-P9: addis [[REG1:[0-9]+]], 2, [[VAR]]@toc at ha
-; CHECK-P9: addi [[REG1]], {{[0-9]+}}, [[VAR]]@toc at l
-; CHECK-P9: lfd {{[0-9]+}}, 0([[REG1]])
+; CHECK-P9: lfd {{[0-9]+}}, [[VAR]]@toc at l([[REG1]])

Added: llvm/trunk/test/CodeGen/PowerPC/toc-float.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/toc-float.ll?rev=335024&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/toc-float.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/toc-float.ll Mon Jun 18 23:54:51 2018
@@ -0,0 +1,71 @@
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 <%s | FileCheck %s
+
+; As the constant could be represented as float, a float is
+; loaded from constant pool.
+define double @doubleConstant1() {
+  ret double 1.400000e+01
+}
+
+; CHECK-LABEL: doubleConstant1:
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha
+; CHECK: lfs {{[0-9]+}}, [[VAR]]@toc at l([[REG1]])
+
+; As the constant couldn't be represented as float, a double is
+; loaded from constant pool.
+define double @doubleConstant2() {
+  ret double 2.408904e+01
+}
+
+; CHECK-LABEL: doubleConstant2:
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha
+; CHECK: lfd {{[0-9]+}}, [[VAR]]@toc at l([[REG1]])
+
+ at FArr = hidden local_unnamed_addr global [10 x float] zeroinitializer, align 4
+
+define float @floatConstantArray() local_unnamed_addr  {
+  %1 = load float, float* getelementptr inbounds ([10 x float], [10 x float]* @FArr, i64 0, i64 3), align 4
+  %2 = fadd float %1, 0x400B333340000000
+  ret float %2
+}
+
+; CHECK-LABEL: floatConstantArray 
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha+[[REG2:[0-9]+]]
+; CHECK: lfs {{[0-9]+}}, [[VAR]]@toc at l+[[REG2]]([[REG1]])
+
+define float @floatConstant() {
+  ret float 0x400470A3E0000000
+}
+
+; CHECK-LABEL: floatConstant:
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha
+; CHECK: lfs {{[0-9]+}}, [[VAR]]@toc at l([[REG1]])
+
+; llvm put the hidden globals into the TOC table.
+; TODO - do some analysis and decide which globals could be put into TOC.
+ at d = hidden local_unnamed_addr global [200 x double] zeroinitializer, align 8
+
+define double @doubleConstantArray()  {
+  %1 = load double, double* getelementptr inbounds ([200 x double], [200 x double]* @d, i64 0, i64 3), align 8
+  %2 = fadd double %1, 6.880000e+00
+  ret double %2
+}
+
+; CHECK-LABEL: doubleConstantArray
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha+[[REG2:[0-9]+]]
+; CHECK: lfd {{[0-9]+}}, [[VAR]]@toc at l+[[REG2]]([[REG1]])
+
+ at arr = hidden local_unnamed_addr global [20000 x double] zeroinitializer, align 8
+
+define double @doubleLargeConstantArray()  {
+  %1 = load double, double* getelementptr inbounds ([20000 x double], [20000 x double]* @arr, i64 0, i64 4096), align 8
+  %2 = fadd double %1, 6.880000e+00
+  ret double %2
+}
+
+; access element that out of range
+; CHECK-LABEL: doubleLargeConstantArray
+; CHECK: addis [[REG1:[0-9]+]], 2, [[VAR:[a-z0-9A-Z_.]+]]@toc at ha
+; CHECK: li [[REG2:[0-9]+]], 0 
+; CHECK: addi [[REG3:[0-9]+]], [[REG1]], [[VAR:[a-z0-9A-Z_.]+]]@toc at l
+; CHECK: ori [[REG4:[0-9]+]], [[REG2]], 32768 
+; CHECK: lfdx {{[0-9]+}}, [[REG3]], [[REG4]] 




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