freedreno/ir3: Add support for disasm of cat2 float32 immediates.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4736>

src/freedreno/ir3/disasm-a3xx.c

@@ -88,7 +88,23 @@ struct disasm_ctx {
 	unsigned instructions;
 };
 
-static void print_reg(struct disasm_ctx *ctx, reg_t reg, bool full, bool r,
+static const char *float_imms[] = {
+	"0.0",
+	"0.5",
+	"1.0",
+	"2.0",
+	"e",
+	"pi",
+	"1/pi",
+	"1/log2(e)",
+	"log2(e)",
+	"1/log2(10)",
+	"log2(10)",
+	"4.0",
+};
+
+static void print_reg(struct disasm_ctx *ctx, reg_t reg, bool full,
+		bool is_float, bool r,
 		bool c, bool im, bool neg, bool abs, bool addr_rel)
 {
 	const char type = c ? 'c' : 'r';
@@ -107,7 +123,11 @@ static void print_reg(struct disasm_ctx *ctx, reg_t reg, bool full, bool r,
 		fprintf(ctx->out, "(r)");
 
 	if (im) {
-		fprintf(ctx->out, "%d", reg.iim_val);
+		if (is_float && full && reg.iim_val < ARRAY_SIZE(float_imms)) {
+			fprintf(ctx->out, "(%s)", float_imms[reg.iim_val]);
+		} else {
+			fprintf(ctx->out, "%d", reg.iim_val);
+		}
 	} else if (addr_rel) {
 		/* I would just use %+d but trying to make it diff'able with
 		 * libllvm-a3xx...
@@ -146,7 +166,7 @@ static reg_t idxreg(unsigned idx)
 static void print_reg_dst(struct disasm_ctx *ctx, reg_t reg, bool full, bool addr_rel)
 {
 	reg = idxreg(regidx(reg) + ctx->repeatidx);
-	print_reg(ctx, reg, full, false, false, false, false, false, addr_rel);
+	print_reg(ctx, reg, full, false, false, false, false, false, false, addr_rel);
 }
 
 /* TODO switch to using reginfo struct everywhere, since more readable
@@ -158,6 +178,7 @@ struct reginfo {
 	bool full;
 	bool r;
 	bool c;
+	bool f; /* src reg is interpreted as float, used for printing immediates */
 	bool im;
 	bool neg;
 	bool abs;
@@ -171,7 +192,7 @@ static void print_src(struct disasm_ctx *ctx, struct reginfo *info)
 	if (info->r)
 		reg = idxreg(regidx(info->reg) + ctx->repeatidx);
 
-	print_reg(ctx, reg, info->full, info->r, info->c, info->im,
+	print_reg(ctx, reg, info->full, info->f, info->r, info->c, info->im,
 			info->neg, info->abs, info->addr_rel);
 }
 
@@ -273,6 +294,7 @@ static void print_instr_cat1(struct disasm_ctx *ctx, instr_t *instr)
 static void print_instr_cat2(struct disasm_ctx *ctx, instr_t *instr)
 {
 	instr_cat2_t *cat2 = &instr->cat2;
+	int opc = _OPC(2, cat2->opc);
 	static const char *cond[] = {
 			"lt",
 			"le",
@@ -283,7 +305,7 @@ static void print_instr_cat2(struct disasm_ctx *ctx, instr_t *instr)
 			"?6?",
 	};
 
-	switch (_OPC(2, cat2->opc)) {
+	switch (opc) {
 	case OPC_CMPS_F:
 	case OPC_CMPS_U:
 	case OPC_CMPS_S:
@@ -303,6 +325,7 @@ static void print_instr_cat2(struct disasm_ctx *ctx, instr_t *instr)
 	struct reginfo src1 = {
 		.full = cat2->full,
 		.r = cat2->repeat ? cat2->src1_r : 0,
+		.f = is_cat2_float(opc),
 		.im = cat2->src1_im,
 		.abs = cat2->src1_abs,
 		.neg = cat2->src1_neg,
@@ -323,11 +346,12 @@ static void print_instr_cat2(struct disasm_ctx *ctx, instr_t *instr)
 	struct reginfo src2 = {
 		.r = cat2->repeat ? cat2->src2_r : 0,
 		.full = cat2->full,
+		.f = is_cat2_float(opc),
 		.abs = cat2->src2_abs,
 		.neg = cat2->src2_neg,
 		.im = cat2->src2_im,
 	};
-	switch (_OPC(2, cat2->opc)) {
+	switch (opc) {
 	case OPC_ABSNEG_F:
 	case OPC_ABSNEG_S:
 	case OPC_CLZ_B:

src/freedreno/ir3/instr-a3xx.h

@@ -1050,6 +1050,43 @@ static inline bool is_isam(opc_t opc)
 	}
 }
 
+
+static inline bool is_cat2_float(opc_t opc)
+{
+	switch (opc) {
+	case OPC_ADD_F:
+	case OPC_MIN_F:
+	case OPC_MAX_F:
+	case OPC_MUL_F:
+	case OPC_SIGN_F:
+	case OPC_CMPS_F:
+	case OPC_ABSNEG_F:
+	case OPC_CMPV_F:
+	case OPC_FLOOR_F:
+	case OPC_CEIL_F:
+	case OPC_RNDNE_F:
+	case OPC_RNDAZ_F:
+	case OPC_TRUNC_F:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static inline bool is_cat3_float(opc_t opc)
+{
+	switch (opc) {
+	case OPC_MAD_F16:
+	case OPC_MAD_F32:
+	case OPC_SEL_F16:
+	case OPC_SEL_F32:
+		return true;
+	default:
+		return false;
+	}
+}
+
 int disasm_a3xx(uint32_t *dwords, int sizedwords, int level, FILE *out, unsigned gpu_id);
 
 #endif /* INSTR_A3XX_H_ */

src/freedreno/ir3/ir3.h

@@ -957,42 +957,6 @@ static inline bool ir3_cat2_int(opc_t opc)
 	}
 }
 
-static inline bool ir3_cat2_float(opc_t opc)
-{
-	switch (opc) {
-	case OPC_ADD_F:
-	case OPC_MIN_F:
-	case OPC_MAX_F:
-	case OPC_MUL_F:
-	case OPC_SIGN_F:
-	case OPC_CMPS_F:
-	case OPC_ABSNEG_F:
-	case OPC_CMPV_F:
-	case OPC_FLOOR_F:
-	case OPC_CEIL_F:
-	case OPC_RNDNE_F:
-	case OPC_RNDAZ_F:
-	case OPC_TRUNC_F:
-		return true;
-
-	default:
-		return false;
-	}
-}
-
-static inline bool ir3_cat3_float(opc_t opc)
-{
-	switch (opc) {
-	case OPC_MAD_F16:
-	case OPC_MAD_F32:
-	case OPC_SEL_F16:
-	case OPC_SEL_F32:
-		return true;
-	default:
-		return false;
-	}
-}
-
 /* map cat2 instruction to valid abs/neg flags: */
 static inline unsigned ir3_cat2_absneg(opc_t opc)
 {

src/freedreno/ir3/ir3_cp.c

@@ -478,8 +478,8 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
 		if (!valid_flags(instr, n, new_flags)) {
 			/* See if lowering an immediate to const would help. */
 			if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
-				bool f_opcode = (ir3_cat2_float(instr->opc) ||
+				bool f_opcode = (is_cat2_float(instr->opc) ||
-						ir3_cat3_float(instr->opc)) ? true : false;
+						is_cat3_float(instr->opc)) ? true : false;
 
 				debug_assert(new_flags & IR3_REG_IMMED);
 
@@ -533,7 +533,7 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
 			if (src->cat1.dst_type == TYPE_F16) {
 				if (instr->opc == OPC_MOV && !type_float(instr->cat1.src_type))
 					return false;
-				if (!ir3_cat2_float(instr->opc) && !ir3_cat3_float(instr->opc))
+				if (!is_cat2_float(instr->opc) && !is_cat3_float(instr->opc))
 					return false;
 			}
 
@@ -594,8 +594,8 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
 
 				return true;
 			} else if (valid_flags(instr, n, (new_flags & ~IR3_REG_IMMED) | IR3_REG_CONST)) {
-				bool f_opcode = (ir3_cat2_float(instr->opc) ||
+				bool f_opcode = (is_cat2_float(instr->opc) ||
-						ir3_cat3_float(instr->opc)) ? true : false;
+						is_cat3_float(instr->opc)) ? true : false;
 
 				/* See if lowering an immediate to const would help. */
 				instr->regs[n+1] = lower_immed(ctx, src_reg, new_flags, f_opcode);

src/freedreno/ir3/tests/disasm.c

@@ -77,6 +77,20 @@ static const struct test {
 	/* discard stuff */
 	INSTR_6XX(42b400f8_20010004, "cmps.s.eq p0.x, r1.x, 1"),
 	INSTR_6XX(02800000_00000000, "kill p0.x"),
+
+	/* Immediates */
+	INSTR_6XX(40100007_68000008, "add.f r1.w, r2.x, (neg)(0.0)"),
+	INSTR_6XX(40100007_68010008, "add.f r1.w, r2.x, (neg)(0.5)"),
+	INSTR_6XX(40100007_68020008, "add.f r1.w, r2.x, (neg)(1.0)"),
+	INSTR_6XX(40100007_68030008, "add.f r1.w, r2.x, (neg)(2.0)"),
+	INSTR_6XX(40100007_68040008, "add.f r1.w, r2.x, (neg)(e)"),
+	INSTR_6XX(40100007_68050008, "add.f r1.w, r2.x, (neg)(pi)"),
+	INSTR_6XX(40100007_68060008, "add.f r1.w, r2.x, (neg)(1/pi)"),
+	INSTR_6XX(40100007_68070008, "add.f r1.w, r2.x, (neg)(1/log2(e))"),
+	INSTR_6XX(40100007_68080008, "add.f r1.w, r2.x, (neg)(log2(e))"),
+	INSTR_6XX(40100007_68090008, "add.f r1.w, r2.x, (neg)(1/log2(10))"),
+	INSTR_6XX(40100007_680a0008, "add.f r1.w, r2.x, (neg)(log2(10))"),
+	INSTR_6XX(40100007_680b0008, "add.f r1.w, r2.x, (neg)(4.0)"),
 };
 
 static void