fix conv_conv optimisation, first optimize IncSP_IncSP then push pop

[r16226]

diff --git a/ir/be/ia32/ia32_optimize.c b/ir/be/ia32/ia32_optimize.c
index daecdbd..45295ce 100644 (file)
--- a/ir/be/ia32/ia32_optimize.c
+++ b/ir/be/ia32/ia32_optimize.c
@@ -285,12 +285,12 @@ static void peephole_be_IncSP(ir_node *node)
        ir_node               *stack;
        int                    offset;
 
-       /* transform IncSP->Store combinations to Push where possible */
-       peephole_IncSP_Store_to_push(node);
-
        /* first optimize incsp->incsp combinations */
        peephole_IncSP_IncSP(node);
 
+       /* transform IncSP->Store combinations to Push where possible */
+       peephole_IncSP_Store_to_push(node);
+
        /* replace IncSP -4 by Pop freereg when possible */
        offset = be_get_IncSP_offset(node);
        if(offset != -4)
@@ -710,6 +710,8 @@ static void optimize_conv_conv(ir_node *node)
 {
        ir_node *pred_proj, *pred, *result_conv;
        ir_mode *pred_mode, *conv_mode;
+       int      conv_mode_bits;
+       int      pred_mode_bits;
 
        if (!is_ia32_Conv_I2I(node) && !is_ia32_Conv_I2I8Bit(node))
                return;
@@ -726,11 +728,17 @@ static void optimize_conv_conv(ir_node *node)
 
        /* we know that after a conv, the upper bits are sign extended
         * so we only need the 2nd conv if it shrinks the mode */
-       conv_mode = get_ia32_ls_mode(node);
-       pred_mode = get_ia32_ls_mode(pred);
-       /* if 2nd conv is smaller then first conv, then we can always take the 2nd
-        * conv */
-       if(get_mode_size_bits(conv_mode) <= get_mode_size_bits(pred_mode)) {
+       conv_mode      = get_ia32_ls_mode(node);
+       conv_mode_bits = get_mode_size_bits(conv_mode);
+       pred_mode      = get_ia32_ls_mode(pred);
+       pred_mode_bits = get_mode_size_bits(pred_mode);
+
+       if(conv_mode_bits == pred_mode_bits
+                       && get_mode_sign(conv_mode) == get_mode_sign(pred_mode)) {
+               result_conv = pred_proj;
+       } else if(conv_mode_bits <= pred_mode_bits) {
+               /* if 2nd conv is smaller then first conv, then we can always take the
+                * 2nd conv */
                if(get_irn_n_edges(pred_proj) == 1) {
                        result_conv = pred_proj;
                        set_ia32_ls_mode(pred, conv_mode);