pan/midgard: Fix invert fusing with r26

The invert wasn't applying (correctly) due to the issues addressed here.

Signed-off-by: Alyssa Rosenzweig <[email protected]>

2 files changed, 19 insertions, 2 deletions

diff --git a/src/panfrost/midgard/midgard_opt_invert.c b/src/panfrost/midgard/midgard_opt_invert.c
index da0cff88649..c3dc8142663 100644
--- a/src/panfrost/midgard/midgard_opt_invert.c
+++ b/src/panfrost/midgard/midgard_opt_invert.c
@@ -193,6 +193,9 @@ midgard_opt_fuse_dest_invert(compiler_context *ctx, midgard_block *block)
 static bool
 mir_strip_inverted(compiler_context *ctx, unsigned node)
 {
+        if (node >= SSA_FIXED_MINIMUM)
+                return false;
+
        /* Strips and returns the invert off a node */
        mir_foreach_instr_global(ctx, ins) {
                if (ins->compact_branch) continue;
@@ -206,6 +209,12 @@ mir_strip_inverted(compiler_context *ctx, unsigned node)
        unreachable("Invalid node stripped");
 }
 
+static bool
+is_ssa_or_constant(unsigned node)
+{
+        return !(node & IS_REG) || (node == SSA_FIXED_REGISTER(26));
+}
+
 bool
 midgard_opt_fuse_src_invert(compiler_context *ctx, midgard_block *block)
 {
@@ -217,8 +226,8 @@ midgard_opt_fuse_src_invert(compiler_context *ctx, midgard_block *block)
                 if (!mir_is_bitwise(ins)) continue;
                 if (ins->invert) continue;
 
-                if (ins->src[0] & IS_REG) continue;
-                if (ins->src[1] & IS_REG) continue;
+                if (!is_ssa_or_constant(ins->src[0])) continue;
+                if (!is_ssa_or_constant(ins->src[1])) continue;
                 if (!mir_single_use(ctx, ins->src[0])) continue;
                 if (!ins->has_inline_constant && !mir_single_use(ctx, ins->src[1])) continue;
 
@@ -252,6 +261,10 @@ midgard_opt_fuse_src_invert(compiler_context *ctx, midgard_block *block)
                                 unsigned temp = ins->src[0];
                                 ins->src[0] = ins->src[1];
                                 ins->src[1] = temp;
+
+                                temp = ins->alu.src1;
+                                ins->alu.src1 = ins->alu.src2;
+                                ins->alu.src2 = temp;
                         }
 
                         ins->alu.op = mir_notright_op(ins->alu.op);
diff --git a/src/panfrost/midgard/mir.c b/src/panfrost/midgard/mir.c
index 0bf4c1d6021..e7129672344 100644
--- a/src/panfrost/midgard/mir.c
+++ b/src/panfrost/midgard/mir.c
@@ -231,6 +231,10 @@ mir_use_count(compiler_context *ctx, unsigned value)
 bool
 mir_single_use(compiler_context *ctx, unsigned value)
 {
+        /* We can replicate constants in places so who cares */
+        if (value == SSA_FIXED_REGISTER(REGISTER_CONSTANT))
+                return true;
+
         return mir_use_count(ctx, value) <= 1;
 }