emit add/sub registers instructions in integrated ARM assembler.

src/DartARM32/assembler_arm.h

@@ -158,6 +158,8 @@ class Operand : public ValueObject {
   }
 #endif
 
+#if 0
+  // Moved to encodeShiftRotateImm5()
   // Data-processing operands - Logical shift/rotate by immediate.
   Operand(Register rm, Shift shift, uint32_t shift_imm) {
     ASSERT(shift_imm < (1 << kShiftImmBits));
@@ -166,6 +168,7 @@ class Operand : public ValueObject {
                 static_cast<uint32_t>(shift) << kShiftShift |
                 static_cast<uint32_t>(rm);
   }
+#endif
 
   // Data-processing operands - Logical shift/rotate by register.
   Operand(Register rm, Shift shift, Register rs) {

tests_lit/assembler/arm32/add.ll

 ; Show that we know how to translate add.
-; TODO(kschimpf) Currently only know how to test add 1 to R0.
 
 ; NOTE: We use -O2 to get rid of memory stores.
 
@@ -17,7 +16,7 @@ define internal i32 @add1ToR0(i32 %p) {
 
 ; ASM-LABEL: add1ToR0:
 ; ASM:       add     r0, r0, #1
-; ASM:  bx      lr
+; ASM-NEXT:  bx      lr
 
 ; IASM-LABEL: add1ToR0:
 ; IASM:      .byte 0x1
@@ -25,3 +24,18 @@ define internal i32 @add1ToR0(i32 %p) {
 ; IASM-NEXT: .byte 0x80
 ; IASM-NEXT: .byte 0xe2
 
+define internal i32 @Add2Regs(i32 %p1, i32 %p2) {
+  %v = add i32 %p1, %p2
+  ret i32 %v
+}
+
+; ASM-LABEL: Add2Regs:
+; ASM:       add r0, r0, r1
+; ASM-NEXT:  bx lr
+
+; IASM-LABEL: Add2Regs:
+
+; IASM:      .byte 0x1
+; IASM-NEXT: .byte 0x0
+; IASM-NEXT: .byte 0x80
+; IASM-NEXT: .byte 0xe0

tests_lit/assembler/arm32/sub.ll

 ; Show that we know how to translate instruction sub.
-; TODO(kschimpf) Currently only know how to test subtract 1 from R0.
 
 ; NOTE: We use -O2 to get rid of memory stores.
 
@@ -25,3 +24,20 @@ define internal i32 @sub1FromR0(i32 %p) {
 ; IASM-NEXT: .byte 0x40
 ; IASM-NEXT: .byte 0xe2
 
+
+define internal i32 @Sub2Regs(i32 %p1, i32 %p2) {
+  %v = sub i32 %p1, %p2
+  ret i32 %v
+}
+
+; ASM-LABEL: Sub2Regs:
+; ASM:       sub r0, r0, r1
+; ASM-NEXT:  bx lr
+
+; IASM-LABEL: Sub2Regs:
+
+; IASM:      .byte 0x1
+; IASM-NEXT: .byte 0x0
+; IASM-NEXT: .byte 0x40
+; IASM-NEXT: .byte 0xe0
+