testing upper_bits in constants is easy too

[r22155]

diff --git a/ir/be/ia32/ia32_transform.c b/ir/be/ia32/ia32_transform.c
index b52656e..82a91c4 100644 (file)
--- a/ir/be/ia32/ia32_transform.c
+++ b/ir/be/ia32/ia32_transform.c
@@ -2751,7 +2751,7 @@ static bool upper_bits_clean(ir_node *transformed_node, ir_mode *mode)
 
        if (is_ia32_Shr(transformed_node) && !mode_is_signed(mode)) {
                ir_node *right = get_irn_n(transformed_node, n_ia32_Shr_count);
-               if (is_ia32_Immediate(right)) {
+               if (is_ia32_Immediate(right) || is_ia32_Const(right)) {
                        const ia32_immediate_attr_t *attr
                                = get_ia32_immediate_attr_const(right);
                        if (attr->symconst == 0
@@ -2763,7 +2763,7 @@ static bool upper_bits_clean(ir_node *transformed_node, ir_mode *mode)
 
        if (is_ia32_And(transformed_node) && !mode_is_signed(mode)) {
                ir_node *right = get_irn_n(transformed_node, n_ia32_And_right);
-               if (is_ia32_Immediate(right)) {
+               if (is_ia32_Immediate(right) || is_ia32_Const(right)) {
                        const ia32_immediate_attr_t *attr
                                = get_ia32_immediate_attr_const(right);
                        if (attr->symconst == 0
@@ -2774,6 +2774,22 @@ static bool upper_bits_clean(ir_node *transformed_node, ir_mode *mode)
                }
        }
 
+       if (is_ia32_Immediate(transformed_node)
+                       || is_ia32_Const(transformed_node)) {
+               const ia32_immediate_attr_t *attr
+                       = get_ia32_immediate_attr_const(transformed_node);
+               if (mode_is_signed(mode)) {
+                       long shifted = attr->offset >> (get_mode_size_bits(mode) - 1);
+                       if (shifted == 0 || shifted == -1)
+                               return true;
+               } else {
+                       unsigned long shifted = (unsigned long) attr->offset;
+                       shifted >>= get_mode_size_bits(mode);
+                       if (shifted == 0)
+                               return true;
+               }
+       }
+
        return false;
 }