[x86] translating "fp" (floating point) instructions from {fadd,fdiv,fmul,fsub,fsubr,fdivr} to {faddp,fdivp,fmulp,fsubp,fsubrp,fdivrp}

LLVM Missing the following instructions: fadd\fdiv\fmul\fsub\fsubr\fdivr.
GAS and MS supporting this instruction and lowering them in to a faddp\fdivp\fmulp\fsubp\fsubrp\fdivrp instructions.

Differential Revision: http://reviews.llvm.org/D14217

llvm-svn: 252908

2 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 1760bce4a35..b7a0e1d7027 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -2218,6 +2218,20 @@ bool X86AsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
       (isPrefix && getLexer().is(AsmToken::Slash)))
     Parser.Lex();
 
+  // This is for gas compatibility and cannot be done in td.
+  // Adding "p" for some floating point with no argument.
+  // For example: fsub --> fsubp
+  bool IsFp =
+    Name == "fsub" || Name == "fdiv" || Name == "fsubr" || Name == "fdivr";
+  if (IsFp && Operands.size() == 1) {
+    const char *Repl = StringSwitch<const char *>(Name)
+      .Case("fsub", "fsubp")
+      .Case("fdiv", "fdivp")
+      .Case("fsubr", "fsubrp")
+      .Case("fdivr", "fdivrp");
+    static_cast<X86Operand &>(*Operands[0]).setTokenValue(Repl);
+  }
+
   // This is a terrible hack to handle "out[bwl]? %al, (%dx)" ->
   // "outb %al, %dx".  Out doesn't take a memory form, but this is a widely
   // documented form in various unofficial manuals, so a lot of code uses it.
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index 9bf0d6d3ffa..0571b07d2f8 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -2793,8 +2793,10 @@ def : InstAlias<"idiv{q}\t{$src, %rax|rax, $src}", (IDIV64m i64mem:$src)>;
 // Various unary fpstack operations default to operating on on ST1.
 // For example, "fxch" -> "fxch %st(1)"
 def : InstAlias<"faddp",        (ADD_FPrST0  ST1), 0>;
+def:  InstAlias<"fadd",         (ADD_FPrST0  ST1), 0>;
 def : InstAlias<"fsub{|r}p",    (SUBR_FPrST0 ST1), 0>;
 def : InstAlias<"fsub{r|}p",    (SUB_FPrST0  ST1), 0>;
+def : InstAlias<"fmul",         (MUL_FPrST0  ST1), 0>;
 def : InstAlias<"fmulp",        (MUL_FPrST0  ST1), 0>;
 def : InstAlias<"fdiv{|r}p",    (DIVR_FPrST0 ST1), 0>;
 def : InstAlias<"fdiv{r|}p",    (DIV_FPrST0  ST1), 0>;