[PATCH] D21819: [Docs][CodeGenerator] Don't specify the number of operands in BuildMI
Visoiu Mistrih Francis via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 29 07:09:33 PDT 2016
thegameg updated this revision to Diff 62221.
thegameg added a comment.
`TTI` -> `TII`.
Thank you for your patience :/.
http://reviews.llvm.org/D21819
Files:
docs/CodeGenerator.rst
include/llvm/CodeGen/MachineInstrBuilder.h
Index: include/llvm/CodeGen/MachineInstrBuilder.h
===================================================================
--- include/llvm/CodeGen/MachineInstrBuilder.h
+++ include/llvm/CodeGen/MachineInstrBuilder.h
@@ -10,7 +10,9 @@
// This file exposes a function named BuildMI, which is useful for dramatically
// simplifying how MachineInstr's are created. It allows use of code like this:
//
-// M = BuildMI(X86::ADDrr8, 2).addReg(argVal1).addReg(argVal2);
+// M = BuildMI(MBB, MI, DL, TII.get(X86::ADD8rr), Dst)
+// .addReg(argVal1)
+// .addReg(argVal2);
//
//===----------------------------------------------------------------------===//
Index: docs/CodeGenerator.rst
===================================================================
--- docs/CodeGenerator.rst
+++ docs/CodeGenerator.rst
@@ -386,32 +386,27 @@
.. code-block:: c++
// Create a 'DestReg = mov 42' (rendered in X86 assembly as 'mov DestReg, 42')
- // instruction. The '1' specifies how many operands will be added.
- MachineInstr *MI = BuildMI(X86::MOV32ri, 1, DestReg).addImm(42);
-
- // Create the same instr, but insert it at the end of a basic block.
+ // instruction and insert it at the end of the given MachineBasicBlock.
+ const TargetInstrInfo &TII = ...
MachineBasicBlock &MBB = ...
- BuildMI(MBB, X86::MOV32ri, 1, DestReg).addImm(42);
+ DebugLoc DL;
+ MachineInstr *MI = BuildMI(MBB, DL, TII.get(X86::MOV32ri), DestReg).addImm(42);
// Create the same instr, but insert it before a specified iterator point.
MachineBasicBlock::iterator MBBI = ...
- BuildMI(MBB, MBBI, X86::MOV32ri, 1, DestReg).addImm(42);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), DestReg).addImm(42);
// Create a 'cmp Reg, 0' instruction, no destination reg.
- MI = BuildMI(X86::CMP32ri, 2).addReg(Reg).addImm(0);
+ MI = BuildMI(MBB, DL, TII.get(X86::CMP32ri8)).addReg(Reg).addImm(42);
// Create an 'sahf' instruction which takes no operands and stores nothing.
- MI = BuildMI(X86::SAHF, 0);
+ MI = BuildMI(MBB, DL, TII.get(X86::SAHF));
// Create a self looping branch instruction.
- BuildMI(MBB, X86::JNE, 1).addMBB(&MBB);
-
-The key thing to remember with the ``BuildMI`` functions is that you have to
-specify the number of operands that the machine instruction will take. This
-allows for efficient memory allocation. You also need to specify if operands
-default to be uses of values, not definitions. If you need to add a definition
-operand (other than the optional destination register), you must explicitly mark
-it as such:
+ BuildMI(MBB, DL, TII.get(X86::JNE)).addMBB(&MBB);
+
+If you need to add a definition operand (other than the optional destination
+register), you must explicitly mark it as such:
.. code-block:: c++
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