[X86] Merge the different CMOV instructions for each condition code into single instructions that store the condition code as an immediate.

Summary:
Reorder the condition code enum to match their encodings. Move it to MC layer so it can be used by the scheduler models.

This avoids needing an isel pattern for each condition code. And it removes
translation switches for converting between CMOV instructions and condition
codes.

Now the printer, encoder and disassembler take care of converting the immediate.
We use InstAliases to handle the assembly matching. But we print using the
asm string in the instruction definition. The instruction itself is marked
IsCodeGenOnly=1 to hide it from the assembly parser.

This does complicate the scheduler models a little since we can't assign the
A and BE instructions to a separate class now.

I plan to make similar changes for SETcc and Jcc.

Reviewers: RKSimon, spatel, lebedev.ri, andreadb, courbet

Reviewed By: RKSimon

Subscribers: gchatelet, hiraditya, kristina, lebedev.ri, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60041

llvm-svn: 357800

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp b/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
index 0f8dc1f39c6..8b110f8c8a5 100644
--- a/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
@@ -227,19 +227,20 @@ TEST_F(UopsSnippetGeneratorTest, SerialInstruction) {
 }
 
 TEST_F(UopsSnippetGeneratorTest, StaticRenaming) {
-  // CMOVA32rr has tied variables, we enumerate the possible values to execute
+  // CMOV32rr has tied variables, we enumerate the possible values to execute
   // as many in parallel as possible.
 
-  // - CMOVA32rr
+  // - CMOV32rr
   // - Op0 Explicit Def RegClass(GR32)
   // - Op1 Explicit Use RegClass(GR32) TiedToOp0
   // - Op2 Explicit Use RegClass(GR32)
+  // - Op3 Explicit Use Immediate
   // - Op3 Implicit Use Reg(EFLAGS)
   // - Var0 [Op0,Op1]
   // - Var1 [Op2]
   // - hasTiedRegisters (execution is always serial)
   // - hasAliasingRegisters
-  const unsigned Opcode = llvm::X86::CMOVA32rr;
+  const unsigned Opcode = llvm::X86::CMOV32rr;
   const auto CodeTemplates = checkAndGetCodeTemplates(Opcode);
   ASSERT_THAT(CodeTemplates, SizeIs(1));
   const auto &CT = CodeTemplates[0];
@@ -249,7 +250,7 @@ TEST_F(UopsSnippetGeneratorTest, StaticRenaming) {
   ASSERT_THAT(CT.Instructions, SizeIs(kInstructionCount));
   std::unordered_set<unsigned> AllDefRegisters;
   for (const auto &IT : CT.Instructions) {
-    ASSERT_THAT(IT.VariableValues, SizeIs(2));
+    ASSERT_THAT(IT.VariableValues, SizeIs(3));
     AllDefRegisters.insert(IT.VariableValues[0].getReg());
   }
   EXPECT_THAT(AllDefRegisters, SizeIs(kInstructionCount))