[X86] Fix incorrect/inefficient pushw encodings for x86-64 targets

Correctly support assembling "pushw $imm8" on x86-64 targets.
Also some cleanup of the PUSH instructions (PUSH64i16 and PUSHi16 actually
represent the same instruction)

This fixes PR23996

Patch by: david.l.kreitzer@intel.com
Differential Revision: http://reviews.llvm.org/D10878

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241404 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index 3e0dc1424609607a2c050846497aa753e34a1962..629802f5dc5e02ef58d57fad02ce9b38bf7760d4 100644 (file)
--- a/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -220,7 +220,6 @@ static unsigned getRelaxedOpcodeArith(unsigned Op) {
   case X86::PUSH32i8:  return X86::PUSHi32;
   case X86::PUSH16i8:  return X86::PUSHi16;
   case X86::PUSH64i8:  return X86::PUSH64i32;
-  case X86::PUSH64i16: return X86::PUSH64i32;
   }
 }
 

diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 6f38cb8eaf33209f5e787c48e817724cd4a6783f..61b474588b773070dbcfba58213fbaa04d74cdd9 100644 (file)
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -1028,14 +1028,13 @@ def PUSH32rmm: I<0xFF, MRM6m, (outs), (ins i32mem:$src), "push{l}\t$src",[],
                  IIC_PUSH_MEM>, OpSize32, Requires<[Not64BitMode]>;
 
 def PUSH16i8 : Ii8<0x6a, RawFrm, (outs), (ins i16i8imm:$imm),
-                   "push{w}\t$imm", [], IIC_PUSH_IMM>, OpSize16,
-                   Requires<[Not64BitMode]>;
+                   "push{w}\t$imm", [], IIC_PUSH_IMM>, OpSize16;
+def PUSHi16  : Ii16<0x68, RawFrm, (outs), (ins i16imm:$imm),
+                   "push{w}\t$imm", [], IIC_PUSH_IMM>, OpSize16;
+
 def PUSH32i8 : Ii8<0x6a, RawFrm, (outs), (ins i32i8imm:$imm),
                    "push{l}\t$imm", [], IIC_PUSH_IMM>, OpSize32,
                    Requires<[Not64BitMode]>;
-def PUSHi16  : Ii16<0x68, RawFrm, (outs), (ins i16imm:$imm),
-                   "push{w}\t$imm", [], IIC_PUSH_IMM>, OpSize16,
-                   Requires<[Not64BitMode]>;
 def PUSHi32  : Ii32<0x68, RawFrm, (outs), (ins i32imm:$imm),
                    "push{l}\t$imm", [], IIC_PUSH_IMM>, OpSize32,
                    Requires<[Not64BitMode]>;
@@ -1081,9 +1080,6 @@ let Defs = [RSP], Uses = [RSP], hasSideEffects = 0, mayStore = 1,
     SchedRW = [WriteStore] in {
 def PUSH64i8   : Ii8<0x6a, RawFrm, (outs), (ins i64i8imm:$imm),
                     "push{q}\t$imm", [], IIC_PUSH_IMM>, Requires<[In64BitMode]>;
-def PUSH64i16  : Ii16<0x68, RawFrm, (outs), (ins i16imm:$imm),
-                    "push{w}\t$imm", [], IIC_PUSH_IMM>, OpSize16,
-                    Requires<[In64BitMode]>;
 def PUSH64i32  : Ii32S<0x68, RawFrm, (outs), (ins i64i32imm:$imm),
                     "push{q}\t$imm", [], IIC_PUSH_IMM>, OpSize32,
                     Requires<[In64BitMode]>;

diff --git a/test/MC/ELF/relax-arith.s b/test/MC/ELF/relax-arith.s
index d4f37a9ddf9f500b39c3c59a8dad62eb742747e3..15e44ebff7ef6f675ee113b5a06c9c999e203315 100644 (file)
--- a/test/MC/ELF/relax-arith.s
+++ b/test/MC/ELF/relax-arith.s
@@ -115,3 +115,11 @@ bar:
         cmpl $foo, bar
         cmp  $foo, %rbx
         cmpq $foo, bar
+
+// CHECK:      Disassembly of section push:
+// CHECK-NEXT: push:
+// CHECK-NEXT:   0: 66 68 00 00                          pushw $0
+// CHECK-NEXT:   4: 68 00 00 00 00                       pushq $0
+        .section push,"x"
+        pushw $foo
+        push  $foo

diff --git a/test/MC/ELF/relax-arith2.s b/test/MC/ELF/relax-arith2.s
index a6c55adf894b7411bf31758788ce00e877791905..b05418482e322a1ef6e7d5747ea1320f98ee9317 100644 (file)
--- a/test/MC/ELF/relax-arith2.s
+++ b/test/MC/ELF/relax-arith2.s
@@ -116,3 +116,15 @@ bar:
         cmpl $1, bar
         cmp  $-1, %rbx
         cmpq $42, bar
+
+// CHECK:      Disassembly of section push:
+// CHECK-NEXT: push:
+// CHECK-NEXT:   0: 66 6a 80                      pushw $-128
+// CHECK-NEXT:   3: 66 6a 7f                      pushw $127
+// CHECK-NEXT:   6: 6a 80                         pushq $-128
+// CHECK-NEXT:   8: 6a 7f                         pushq $127
+        .section push,"x"
+        pushw $-128
+        pushw $127
+        push  $-128
+        push  $127

diff --git a/test/MC/ELF/relax-arith4.s b/test/MC/ELF/relax-arith4.s
new file mode 100644 (file)
index 0000000..3fd3cad
--- /dev/null
+++ b/test/MC/ELF/relax-arith4.s
@@ -0,0 +1,25 @@
+// RUN: llvm-mc -filetype=obj -triple i686-pc-linux-gnu %s -o - | llvm-objdump -d - | FileCheck  %s
+
+// Test for proper instruction relaxation behavior for the push $imm
+// instruction forms. This is the 32-bit version of the push $imm tests from
+// relax-arith.s and relax-arith2.s.
+
+// CHECK:      Disassembly of section push8:
+// CHECK-NEXT: push8:
+// CHECK-NEXT:   0: 66 6a 80                      pushw $-128
+// CHECK-NEXT:   3: 66 6a 7f                      pushw $127
+// CHECK-NEXT:   6: 6a 80                         pushl $-128
+// CHECK-NEXT:   8: 6a 7f                         pushl $127
+        .section push8,"x"
+        pushw $-128
+        pushw $127
+        push  $-128
+        push  $127
+
+// CHECK:      Disassembly of section push32:
+// CHECK-NEXT: push32:
+// CHECK-NEXT:   0: 66 68 00 00                   pushw $0
+// CHECK-NEXT:   4: 68 00 00 00 00                pushl $0
+        .section push32,"x"
+        pushw $foo
+        push  $foo