[mips] Set flag neverHasSideEffects flag on floating point conversion

instructions.

llvm-svn: 167348

3 files changed, 27 insertions, 6 deletions

diff --git a/llvm/lib/Target/Mips/MipsInstrFPU.td b/llvm/lib/Target/Mips/MipsInstrFPU.td
index 441d2e87020..33ee0206894 100644
--- a/llvm/lib/Target/Mips/MipsInstrFPU.td
+++ b/llvm/lib/Target/Mips/MipsInstrFPU.td
@@ -182,20 +182,21 @@ defm CEIL_W  : FFR1_W_M<0xe, "ceil">;
 defm CEIL_L  : FFR1_L_M<0xa, "ceil">;
 defm FLOOR_W : FFR1_W_M<0xf, "floor">;
 defm FLOOR_L : FFR1_L_M<0xb, "floor">;
-defm CVT_W   : FFR1_W_M<0x24, "cvt">;
+defm CVT_W   : FFR1_W_M<0x24, "cvt">, NeverHasSideEffects;
 //defm CVT_L   : FFR1_L_M<0x25, "cvt">;
 
-def CVT_S_W : FFR1<0x20, 20, "cvt", "s.w", FGR32, FGR32>;
-def CVT_L_S : FFR1<0x25, 16, "cvt", "l.s", FGR64, FGR32>;
-def CVT_L_D64: FFR1<0x25, 17, "cvt", "l.d", FGR64, FGR64>;
+def CVT_S_W : FFR1<0x20, 20, "cvt", "s.w", FGR32, FGR32>, NeverHasSideEffects;
+def CVT_L_S : FFR1<0x25, 16, "cvt", "l.s", FGR64, FGR32>, NeverHasSideEffects;
+def CVT_L_D64: FFR1<0x25, 17, "cvt", "l.d", FGR64, FGR64>, NeverHasSideEffects;
 
-let Predicates = [NotFP64bit, HasStandardEncoding] in {
+let Predicates = [NotFP64bit, HasStandardEncoding], neverHasSideEffects = 1 in {
   def CVT_S_D32 : FFR1<0x20, 17, "cvt", "s.d", FGR32, AFGR64>;
   def CVT_D32_W : FFR1<0x21, 20, "cvt", "d.w", AFGR64, FGR32>;
   def CVT_D32_S : FFR1<0x21, 16, "cvt", "d.s", AFGR64, FGR32>;
 }
 
-let Predicates = [IsFP64bit, HasStandardEncoding], DecoderNamespace = "Mips64" in {
+let Predicates = [IsFP64bit, HasStandardEncoding], DecoderNamespace = "Mips64",
+    neverHasSideEffects = 1 in {
  def CVT_S_D64 : FFR1<0x20, 17, "cvt", "s.d", FGR32, FGR64>;
  def CVT_S_L   : FFR1<0x20, 21, "cvt", "s.l", FGR32, FGR64>;
  def CVT_D64_W : FFR1<0x21, 20, "cvt", "d.w", FGR64, FGR32>;
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index 3319553935e..f16b5f9ee7f 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -204,6 +204,10 @@ class IsAsCheapAsAMove {
   bit isAsCheapAsAMove = 1;
 }
 
+class NeverHasSideEffects {
+  bit neverHasSideEffects = 1;
+}
+
 //===----------------------------------------------------------------------===//
 // Instruction format superclass
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/Mips/brdelayslot.ll b/llvm/test/CodeGen/Mips/brdelayslot.ll
index 1b2fbc89321..2fdb736dc88 100644
--- a/llvm/test/CodeGen/Mips/brdelayslot.ll
+++ b/llvm/test/CodeGen/Mips/brdelayslot.ll
@@ -19,3 +19,19 @@ entry:
 }
 
 declare void @foo2(i32)
+
+; Check that cvt.d.w goes into jalr's delay slot.
+;
+define void @foo3(i32 %a) nounwind {
+entry:
+; Default:     foo3:
+; Default:     jalr
+; Default:     cvt.d.w
+
+  %conv = sitofp i32 %a to double
+  tail call void @foo4(double %conv) nounwind
+  ret void
+}
+
+declare void @foo4(double)
+