From d2b58240b4afe314290af951997d705c5714d887 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Tue, 23 Sep 2014 12:56:54 -0700 Subject: [PATCH] vc4: When possible, resolve raddr conflicts by swapping files on specials. Cleans up a bunch of ugliness in perspective interpolation. --- src/gallium/drivers/vc4/vc4_qpu_emit.c | 34 +++++++++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 5 deletions(-) diff --git a/src/gallium/drivers/vc4/vc4_qpu_emit.c b/src/gallium/drivers/vc4/vc4_qpu_emit.c index 985f2c4..bbfefeb 100644 --- a/src/gallium/drivers/vc4/vc4_qpu_emit.c +++ b/src/gallium/drivers/vc4/vc4_qpu_emit.c @@ -67,6 +67,27 @@ set_last_cond_add(struct vc4_compile *c, uint32_t cond) } /** + * Some special registers can be read from either file, which lets us resolve + * raddr conflicts without extra MOVs. + */ +static bool +swap_file(struct qpu_reg *src) +{ + switch (src->addr) { + case QPU_R_UNIF: + case QPU_R_VARY: + if (src->mux == QPU_MUX_A) + src->mux = QPU_MUX_B; + else + src->mux = QPU_MUX_A; + return true; + + default: + return false; + } +} + +/** * This is used to resolve the fact that we might register-allocate two * different operands of an instruction to the same physical register file * even though instructions have only one field for the register file source @@ -77,14 +98,17 @@ set_last_cond_add(struct vc4_compile *c, uint32_t cond) */ static void fixup_raddr_conflict(struct vc4_compile *c, - struct qpu_reg src0, struct qpu_reg *src1) + struct qpu_reg *src0, struct qpu_reg *src1) { - if ((src0.mux != QPU_MUX_A && src0.mux != QPU_MUX_B) || - src0.mux != src1->mux || - src0.addr == src1->addr) { + if ((src0->mux != QPU_MUX_A && src0->mux != QPU_MUX_B) || + src0->mux != src1->mux || + src0->addr == src1->addr) { return; } + if (swap_file(src0) || swap_file(src1)) + return; + queue(c, qpu_a_MOV(qpu_r3(), *src1)); *src1 = qpu_r3(); } @@ -528,7 +552,7 @@ vc4_generate_code(struct vc4_context *vc4, struct vc4_compile *c) if (qir_get_op_nsrc(qinst->op) == 1) src[1] = src[0]; - fixup_raddr_conflict(c, src[0], &src[1]); + fixup_raddr_conflict(c, &src[0], &src[1]); if (translate[qinst->op].is_mul) { queue(c, qpu_m_alu2(translate[qinst->op].op, -- 2.7.4