[Subzero][MIPS32] Implement icmp operation for i8, i16 operands

tests_lit/llvm2ice_tests/icmp.ll

+; Simple tests for icmp with i8, i16, i32 operands.
+
+; RUN: %if --need=allow_dump --need=target_MIPS32 --command %p2i \
+; RUN:   --filetype=asm --target mips32 -i %s --args -O2 --skip-unimplemented \

[Jim Stichnoth, 2016/05/31 19:00:20]

Just a comment and an optional suggestion.

For an early-stage target lowering, and with filetype=asm, I like to lightly try
with both -Om1 and -O2.  Sometimes this reveals incorrect lowering and invalid
addressing modes (leading to llvm-mc errors).  Sometimes "make check-lit" just
works.  In other cases (including this one), pnacl-sz and llvm-mc generate valid
code, but FileCheck complains because the CHECK patterns don't match.

In this case, a cursory examination suggests that the failures are from
overly-specific register assumptions.  It might be worth making the patterns
more general, which could help future-proof the lit tests against future
register allocation or related changes.

[sagar.thakur, 2016/06/01 13:17:22]

Done.

+; RUN:   -allow-externally-defined-symbols \
+; RUN:   | %if --need=allow_dump --need=target_MIPS32 --command FileCheck %s \
+; RUN:   --check-prefix=COMMON --check-prefix=MIPS32
+
+define internal i32 @icmpEq32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp eq i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpEq32
+; MIPS32: xor {{.*}}, $a0, $a1
+; MIPS32: sltiu {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpNe32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp ne i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpNe32
+; MIPS32: xor {{.*}}, $a0, $a1
+; MIPS32: sltu {{.*}}, $zero, {{.*}}
+
+define internal i32 @icmpSgt32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp sgt i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpSgt32
+; MIPS32: slt {{.*}}, $a1, $a0
+
+define internal i32 @icmpUgt32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp ugt i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpUgt32
+; MIPS32: sltu {{.*}}, $a1, $a0
+
+define internal i32 @icmpSge32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp sge i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpSge32
+; MIPS32: slt {{.*}}, $a0, $a1
+; MIPS32: xori {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpUge32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp uge i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpUge32
+; MIPS32: sltu {{.*}}, $a0, $a1
+; MIPS32: xori {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpSlt32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp slt i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpSlt32
+; MIPS32: slt {{.*}}, $a0, $a1
+
+define internal i32 @icmpUlt32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp ult i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpUlt32
+; MIPS32: sltu {{.*}}, $a0, $a1
+
+define internal i32 @icmpSle32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp sle i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpSle32
+; MIPS32: slt {{.*}}, $a1, $a0
+; MIPS32: xori {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpUle32(i32 %a, i32 %b) {
+entry:
+  %cmp = icmp ule i32 %a, %b
+  %cmp.ret_ext = zext i1 %cmp to i32
+  ret i32 %cmp.ret_ext
+}
+; MIPS32-LABEL: icmpUle32
+; MIPS32: sltu {{.*}}, $a1, $a0
+; MIPS32: xori {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpEq8(i32 %a, i32 %b) {
+entry:
+  %a_8 = trunc i32 %a to i8
+  %b_8 = trunc i32 %b to i8
+  %icmp = icmp eq i8 %b_8, %a_8
+  %ret = zext i1 %icmp to i32
+  ret i32 %ret
+}
+; MIPS32-LABEL: icmpEq8
+; MIPS32: andi {{.*}}, $a1, 255
+; MIPS32: andi {{.*}}, $a0, 255
+; MIPS32: xor
+; MIPS32: sltiu {{.*}}, {{.*}}, 1
+
+define internal i32 @icmpSgt8(i32 %a, i32 %b) {
+entry:
+  %a_8 = trunc i32 %a to i8
+  %b_8 = trunc i32 %b to i8
+  %icmp = icmp sgt i8 %b_8, %a_8
+  %ret = zext i1 %icmp to i32
+  ret i32 %ret
+}
+; MIPS32-LABEL: icmpSgt8
+; MIPS32: sll {{.*}}, $a1, 24
+; MIPS32: sra {{.*}}, {{.*}}, 24
+; MIPS32: sll {{.*}}, $a0, 24
+; MIPS32: sra {{.*}}, {{.*}}, 24
+; MIPS32: slt
+
+define internal i32 @icmpUgt8(i32 %a, i32 %b) {
+entry:
+  %a_8 = trunc i32 %a to i8
+  %b_8 = trunc i32 %b to i8
+  %icmp = icmp ugt i8 %b_8, %a_8
+  %ret = zext i1 %icmp to i32
+  ret i32 %ret
+}
+; MIPS32-LABEL: icmpUgt8
+; MIPS32: andi {{.*}}, $a1, 255
+; MIPS32: andi {{.*}}, $a0, 255
+; MIPS32: sltu
+
+define internal i32 @icmpSgt16(i32 %a, i32 %b) {
+entry:
+  %a_16 = trunc i32 %a to i16
+  %b_16 = trunc i32 %b to i16
+  %icmp = icmp sgt i16 %b_16, %a_16
+  %ret = zext i1 %icmp to i32
+  ret i32 %ret
+}
+; MIPS32-LABEL: icmpSgt16
+; MIPS32: sll {{.*}}, $a1, 16
+; MIPS32: sra {{.*}}, {{.*}}, 16
+; MIPS32: sll {{.*}}, $a0, 16
+; MIPS32: sra {{.*}}, {{.*}}, 16
+; MIPS32: slt
+
+define internal i32 @icmpUgt16(i32 %a, i32 %b) {
+entry:
+  %a_16 = trunc i32 %a to i16
+  %b_16 = trunc i32 %b to i16
+  %icmp = icmp ugt i16 %b_16, %a_16
+  %ret = zext i1 %icmp to i32
+  ret i32 %ret
+}
+; MIPS32-LABEL: icmpUgt16
+; MIPS32: andi {{.*}}, $a1, 65535
+; MIPS32: andi {{.*}}, $a0, 65535
+; MIPS32: sltu