------- Comment #3 from vda dot linux at googlemail dot com 2006-08-07 11:26
-------
Differences in *.vrp (-fdump-tree-vrp output) and assembly generated
with stock 4.1.1 and with patched one out of test program test_vrp.c
--- test_vrp.c.t36-411org.vrp 2006-08-06 22:40:04.000000000 +0200
+++ test_vrp.c.t36-411new.vrp 2006-08-06 22:40:20.000000000 +0200
@@ -26,12 +26,15 @@
Value ranges after VRP:
n_1: VARYING
-D.1286_2: VARYING
-D.1287_3: VARYING
+D.1286_2: [256, 256] EQUIVALENCES: { } (0 elements)
+D.1287_3: [0, 1] EQUIVALENCES: { } (0 elements)
n_5: [65793, 65809] EQUIVALENCES: { n_1 n_6 } (2 elements)
n_6: [0, 65809] EQUIVALENCES: { n_1 } (1 elements)
+Folding predicate D.1286_2 != 0 to 1
+Merging blocks 2 and 3
+Merging blocks 2 and 4
u4 (n)
{
_Bool D.1288;
@@ -46,12 +49,7 @@
<L1>:;
D.1286_2 = n_1 & 256;
- if (D.1286_2 != 0) goto <L2>; else goto <L3>;
-
-<L2>:;
f ();
-
-<L3>:;
D.1287_3 = n_1 & 1;
if (D.1287_3 != 0) goto <L4>; else goto <L5>;
@@ -95,16 +93,18 @@
a_1: VARYING
b_2: VARYING
-D.1282_3: VARYING
-D.1282_4: [D.1282_3, D.1282_3] EQUIVALENCES: { D.1282_3 } (1 elements)
+D.1282_3: [4096, +INF] EQUIVALENCES: { } (0 elements)
+D.1282_4: [4096, +INF] EQUIVALENCES: { D.1282_3 } (1 elements)
a_5: [4096, 4096] EQUIVALENCES: { a_1 a_6 } (2 elements)
a_6: [4096, +INF] EQUIVALENCES: { a_1 } (1 elements)
b_7: [272, +INF] EQUIVALENCES: { b_2 } (1 elements)
-D.1282_8: [0, 4095] EQUIVALENCES: { D.1282_3 } (1 elements)
Simplified relational a_6 > 4096 into a_6 != 4096
+Folding predicate D.1282_3 > 4095 to 1
Removing basic block 8
+Merging blocks 3 and 4
+Merging blocks 3 and 5
v4 (a, b)
{
unsigned int D.1282;
@@ -120,12 +120,7 @@
<L2>:;
D.1282_3 = b_2 | 4096;
- if (D.1282_3 > 4095) goto <L3>; else goto <L4>;
-
-<L3>:;
f ();
-
-<L4>:;
D.1282_4 = D.1282_3;
if (D.1282_3 > 65535) goto <L5>; else goto <L6>;
--- test_vrp-411org.s 2006-08-06 22:40:04.000000000 +0200
+++ test_vrp-411new.s 2006-08-06 22:40:20.000000000 +0200
@@ -7,24 +7,20 @@
subl $8, %esp
movl 16(%esp), %ebx
cmpl $65809, %ebx
- ja .L8
+ ja .L6
cmpl $65792, %ebx
- jbe .L8
- testb $1, %bh
- jne .L10
-.L5:
- andl $1, %ebx
- je .L8
+ ja .L8
+.L6:
addl $8, %esp
popl %ebx
- jmp g
+ ret
.L8:
+ call f
+ andl $1, %ebx
+ je .L6
addl $8, %esp
popl %ebx
- ret
-.L10:
- call f
- jmp .L5
+ jmp g
.size u4, .-u4
.globl v4
.type v4, @function
@@ -32,31 +28,25 @@
pushl %ebx
subl $8, %esp
movl 16(%esp), %eax
- movl 20(%esp), %edx
+ movl 20(%esp), %ebx
cmpl $4095, %eax
- jbe .L19
+ jbe .L15
cmpl $4096, %eax
- je .L20
-.L19:
+ je .L16
+.L15:
addl $8, %esp
popl %ebx
ret
-.L20:
- cmpl $271, %edx
- jbe .L19
- movl %edx, %ebx
- orb $16, %bh
- cmpl $4095, %ebx
- ja .L21
.L16:
+ cmpl $271, %ebx
+ jbe .L15
+ call f
+ orb $16, %bh
cmpl $65535, %ebx
- jbe .L19
+ jbe .L15
addl $8, %esp
popl %ebx
jmp g
-.L21:
- call f
- jmp .L16
.size v4, .-v4
.ident "GCC: (GNU) 4.1.1"
.section .note.GNU-stack,"",@progbits
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28632
