[X86] Change the Format attribute for TEST*rr instruction from the default MRMDestReg to MRMSrcReg

[aymanmus]

Summary

Correctly define the TEST{8 | 16 | 32 | 64}rr instructions Format attribute.

[craig.topper]

This is apparently a revert of the fix for https://bugs.llvm.org/show_bug.cgi?id=22995

What is the real right answer? What motivated this change?

[craig.topper]

Did this come out of the folding table work? The real bug is that TEST8rm is wrong. But we don't notice because we have aliases to accept the memory operand in either location.

[aymanmus]

Fixed in D38120

lib/Target/X86/X86InstrArithmetic.td

 // they don't have all the usual imm8 and REV forms, and are encoded into a
 // different space.
 def X86testpat : PatFrag<(ops node:$lhs, node:$rhs),
                          (X86cmp (and_su node:$lhs, node:$rhs), 0)>;
 
 let isCompare = 1 in {
   let Defs = [EFLAGS] in {
     let isCommutable = 1 in {
-      def TEST8rr  : BinOpRR_F<0x84, "test", Xi8 , X86testpat>;
-      def TEST16rr : BinOpRR_F<0x84, "test", Xi16, X86testpat>;
-      def TEST32rr : BinOpRR_F<0x84, "test", Xi32, X86testpat>;
-      def TEST64rr : BinOpRR_F<0x84, "test", Xi64, X86testpat>;
+      def TEST8rr  : BinOpRR_F<0x84, "test", Xi8 , X86testpat, MRMSrcReg>;
+      def TEST16rr : BinOpRR_F<0x84, "test", Xi16, X86testpat, MRMSrcReg>;
+      def TEST32rr : BinOpRR_F<0x84, "test", Xi32, X86testpat, MRMSrcReg>;
+      def TEST64rr : BinOpRR_F<0x84, "test", Xi64, X86testpat, MRMSrcReg>;
     } // isCommutable
 
     def TEST8rm    : BinOpRM_F<0x84, "test", Xi8 , X86testpat>;
     def TEST16rm   : BinOpRM_F<0x84, "test", Xi16, X86testpat>;
     def TEST32rm   : BinOpRM_F<0x84, "test", Xi32, X86testpat>;
     def TEST64rm   : BinOpRM_F<0x84, "test", Xi64, X86testpat>;
 
     def TEST8ri    : BinOpRI_F<0xF6, "test", Xi8 , X86testpat, MRM0r>;

test/MC/Disassembler/X86/x86-16.txt

 0x0f 0x01 0xf9
 
 # CHECK: movl %eax, 16(%ebp)
 0x67 0x66 0x89 0x45 0x10
 
 # CHECK: movl %eax, -16(%ebp)
 0x67 0x66 0x89 0x45 0xf0
 
-# CHECK: testb %cl, %bl
+# CHECK: testb %bl, %cl
 0x84 0xcb
 
 # CHECK: cmpl %eax, %ebx
 0x66 0x39 0xc3
 
 # CHECK: addw %ax, %ax
 0x01 0xc0
 

test/MC/X86/x86-16.s

 // CHECK:  encoding: [0x0f,0x01,0xf9]
 
 
 // CHECK: movl  %eax, 16(%ebp)          # encoding: [0x67,0x66,0x89,0x45,0x10]
   movl  %eax, 16(%ebp)
 // CHECK: movl  %eax, -16(%ebp)          # encoding: [0x67,0x66,0x89,0x45,0xf0]
   movl  %eax, -16(%ebp)
 
-// CHECK: testb %bl, %cl                # encoding: [0x84,0xd9]
+// CHECK: testb %bl, %cl                # encoding: [0x84,0xcb]
         testb %bl, %cl
 
 // CHECK: cmpl  %eax, %ebx              # encoding: [0x66,0x39,0xc3]
         cmpl %eax, %ebx
 
 // CHECK: addw  %ax, %ax                # encoding: [0x01,0xc0]
         addw %ax, %ax
 

test/MC/X86/x86-32.s

 // CHECK:  encoding: [0x0f,0x01,0xf9]
 
 
 // CHECK: movl  %eax, 16(%ebp)          # encoding: [0x89,0x45,0x10]
   movl  %eax, 16(%ebp)
 // CHECK: movl  %eax, -16(%ebp)          # encoding: [0x89,0x45,0xf0]
   movl  %eax, -16(%ebp)
 
-// CHECK: testb %bl, %cl                # encoding: [0x84,0xd9]
+// CHECK: testb %bl, %cl                # encoding: [0x84,0xcb]
         testb %bl, %cl
 
 // CHECK: cmpl  %eax, %ebx              # encoding: [0x39,0xc3]
         cmpl %eax, %ebx
 
 // CHECK: addw  %ax, %ax                # encoding: [0x66,0x01,0xc0]
         addw %ax, %ax
 

test/MC/X86/x86-64.s

 // CHECK:  fixup A - offset: 4, value: _foo@GOTPCREL-4, kind: reloc_riprel_4byte_movq_load
 movq _foo@GOTPCREL(%eip), %r14
 
 // CHECK: movq  (%r13,%rax,8), %r13
 // CHECK:  encoding: [0x4d,0x8b,0x6c,0xc5,0x00]
 movq 0x00(%r13,%rax,8),%r13
 
 // CHECK: testq %rax, %rbx
-// CHECK:  encoding: [0x48,0x85,0xc3]
+// CHECK:  encoding: [0x48,0x85,0xd8]
 testq %rax, %rbx
 
 // CHECK: cmpq  %rbx, %r14
 // CHECK:   encoding: [0x49,0x39,0xde]
         cmpq %rbx, %r14
 
 // rdar://7947167