agx: Add pseudo-instructions for icmp/fcmp

Easier to optimize with.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25052>

src/asahi/compiler/agx_lower_pseudo.c

@@ -65,6 +65,17 @@ lower(agx_builder *b, agx_instr *I)
    case AGX_OPCODE_OR:
       return agx_bitop_to(b, I->dest[0], I->src[0], I->src[1], AGX_BITOP_OR);
 
+   /* Unfused comparisons are fused with a 0/1 select */
+   case AGX_OPCODE_ICMP:
+      return agx_icmpsel_to(b, I->dest[0], I->src[0], I->src[1],
+                            agx_immediate(I->invert_cond ? 0 : 1),
+                            agx_immediate(I->invert_cond ? 1 : 0), I->icond);
+
+   case AGX_OPCODE_FCMP:
+      return agx_fcmpsel_to(b, I->dest[0], I->src[0], I->src[1],
+                            agx_immediate(I->invert_cond ? 0 : 1),
+                            agx_immediate(I->invert_cond ? 1 : 0), I->fcond);
+
    /* Writes to the nesting counter lowered to the real register */
    case AGX_OPCODE_BEGIN_CF:
       return agx_mov_imm_to(b, agx_register(0, AGX_SIZE_16), 0);

src/asahi/compiler/agx_opcodes.py

@@ -251,6 +251,10 @@ op("fcmpsel",
       encoding_32 = (0x02, 0x7F, 8, 10),
       srcs = 4, imms = [FCOND])
 
+# Pseudo-instructions for compares returning 1/0
+op("icmp", _, srcs = 2, imms = [ICOND, INVERT_COND])
+op("fcmp", _, srcs = 2, imms = [FCOND, INVERT_COND])
+
 # sources are coordinates, LOD, texture bindless base (zero for texture state
 # registers), texture, sampler, shadow/offset
 # TODO: anything else?