Implement methods that enable expansion of load immediate

macro instruction (li) in the assembler.

We have identified three possible expansions depending on 
the size of immediate operand:
  1) for 0 ≤ j ≤ 65535.
     li d,j =>
     ori d,$zero,j

  2) for −32768 ≤ j < 0.
     li d,j =>
     addiu d,$zero,j

  3) for any other value of j that is representable as a 32-bit integer.
     li d,j =>
     lui d,hi16(j)
     ori d,d,lo16(j)

All of the above have been implemented in ths patch.

Contributer: Vladimir Medic
llvm-svn: 165199

1 files changed, 14 insertions, 0 deletions

diff --git a/llvm/test/MC/Mips/mips-expansions.s b/llvm/test/MC/Mips/mips-expansions.s
new file mode 100644
index 00000000000..b87bfbdc5b2
--- /dev/null
+++ b/llvm/test/MC/Mips/mips-expansions.s
@@ -0,0 +1,14 @@
+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -show-encoding -mcpu=mips32r2 | FileCheck %s
+# Check that the assembler can handle the documented syntax
+# for macro instructions
+# CHECK: .section __TEXT,__text,regular,pure_instructions
+#------------------------------------------------------------------------------
+# Load immediate instructions
+#------------------------------------------------------------------------------
+# CHECK: ori     $5, $zero, 123      # encoding: [0x7b,0x00,0x05,0x34]
+# CHECK: addiu   $6, $zero, -2345    # encoding: [0xd7,0xf6,0x06,0x24]
+# CHECK: lui     $7, 1               # encoding: [0x01,0x00,0x07,0x3c]
+# CHECK: ori     $7, $7, 2           # encoding: [0x02,0x00,0xe7,0x34]
+    li $5,123
+    li $6,-2345
+    li $7,65538