------- Comment #19 from jakub at gcc dot gnu dot org 2007-09-12 17:49 -------
Here is self-contained source:
void
sys_futex0(int *addr, int op, int val)
{
register long out0 asm ("out0") = (long) addr;
register long out1 asm ("out1") = op;
register long out2 asm ("out2") = val;
register long out3 asm ("out3") = 0;
register long r15 asm ("r15") = 1230;
__asm __volatile ("break 0x100000"
: "=r"(r15), "=r"(out0), "=r"(out1), "=r"(out2), "=r"(out3)
: "r"(r15), "r"(out0), "r"(out1), "r"(out2), "r"(out3)
: "memory", "r8", "r10", "out4", "out5", "out6", "out7",
/* Non-stacked integer registers, minus r8, r10, r15. */
"r2", "r3", "r9", "r11", "r12", "r13", "r14", "r16", "r17", "r18",
"r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27",
"r28", "r29", "r30", "r31",
/* Predicate registers. */
"p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15",
/* Non-rotating fp registers. */
"f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
/* Branch registers. */
"b6");
}
vs.
void
sys_futex0(int *addr, int op, int val)
{
register long out0 asm ("out0") = (long) addr;
register long out1 asm ("out1") = op;
register long out2 asm ("out2") = val;
register long out3 asm ("out3") = 0;
register long r15 asm ("r15") = 1230;
__asm __volatile ("break 0x100000"
:
: "r"(r15), "r"(out0), "r"(out1), "r"(out2), "r"(out3)
: "memory", "r8", "r10", "out4", "out5", "out6", "out7",
/* Non-stacked integer registers, minus r8, r10, r15. */
"r2", "r3", "r9", "r11", "r12", "r13", "r14", "r16", "r17", "r18",
"r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27",
"r28", "r29", "r30", "r31",
/* Predicate registers. */
"p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15",
/* Non-rotating fp registers. */
"f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
/* Branch registers. */
"b6");
}
The former is miscompiled by sdse1 pass:
Deleted dead store '# STORES: { out0D.1189 }
out0D.1189 ={v} addr.0D.1194_2'
Deleted dead store '# STORES: { out1D.1190 }
out1D.1190 ={v} out1.1D.1195_4'
Deleted dead store '# STORES: { out2D.1191 }
out2D.1191 ={v} out2.2D.1196_6'
Deleted dead store '# STORES: { out3D.1192 }
out3D.1192 ={v} 0'
Deleted dead store '# STORES: { r15D.1193 }
r15D.1193 ={v} 1230'
sys_futex0 (addrD.1184, opD.1185, valD.1186)
{
register long intD.2 r15D.1193 __asm__ (*r15);
register long intD.2 out3D.1192 __asm__ (*out3);
register long intD.2 out2D.1191 __asm__ (*out2);
register long intD.2 out1D.1190 __asm__ (*out1);
register long intD.2 out0D.1189 __asm__ (*out0);
long intD.2 out2.2D.1196;
long intD.2 out1.1D.1195;
long intD.2 addr.0D.1194;
# BLOCK 2
# PRED: ENTRY (fallthru,exec)
addr.0D.1194_2 = (long intD.2) addrD.1184_1(D);
out1.1D.1195_4 = (long intD.2) opD.1185_3(D);
out2.2D.1196_6 = (long intD.2) valD.1186_5(D);
# STORES: { out0D.1189 out1D.1190 out2D.1191 out3D.1192 r15D.1193 }
__asm__ __volatile__("break 0x100000":"=r" r15D.1193, "=r" out0D.1189, "=r"
out1D.1190, "=r" out2D.1191, "=r" out3D.1192:"r" r1
5D.1193, "r" out0D.1189, "r" out1D.1190, "r" out2D.1191, "r" out3D.1192:"b6",
"f15", "f14", "f13", "f12", "f11", "f10", "f9", "f8
", "f7", "f6", "p15", "p14", "p13", "p12", "p11", "p10", "p9", "p8", "p7",
"p6", "r31", "r30", "r29", "r28", "r27", "r26", "r25",
"r24", "r23", "r22", "r21", "r20", "r19", "r18", "r17", "r16", "r14", "r13",
"r12", "r11", "r9", "r3", "r2", "out7", "out6", "ou
t5", "out4", "r10", "r8", "memory");
return;
# SUCC: EXIT
while the latter is not:
;; Function sys_futex0 (sys_futex0)
sys_futex0 (addrD.1184, opD.1185, valD.1186)
{
register long intD.2 r15D.1193 __asm__ (*r15);
register long intD.2 out3D.1192 __asm__ (*out3);
register long intD.2 out2D.1191 __asm__ (*out2);
register long intD.2 out1D.1190 __asm__ (*out1);
register long intD.2 out0D.1189 __asm__ (*out0);
long intD.2 out2.2D.1196;
long intD.2 out1.1D.1195;
long intD.2 addr.0D.1194;
# BLOCK 2
# PRED: ENTRY (fallthru,exec)
addr.0D.1194_2 = (long intD.2) addrD.1184_1(D);
# STORES: { out0D.1189 }
out0D.1189 ={v} addr.0D.1194_2;
out1.1D.1195_4 = (long intD.2) opD.1185_3(D);
# STORES: { out1D.1190 }
out1D.1190 ={v} out1.1D.1195_4;
out2.2D.1196_6 = (long intD.2) valD.1186_5(D);
# STORES: { out2D.1191 }
out2D.1191 ={v} out2.2D.1196_6;
# STORES: { out3D.1192 }
out3D.1192 ={v} 0;
# STORES: { r15D.1193 }
r15D.1193 ={v} 1230;
# LOADS: { out0D.1189 out1D.1190 out2D.1191 out3D.1192 r15D.1193 }
__asm__ __volatile__("break 0x100000"::"r" r15D.1193, "r" out0D.1189, "r"
out1D.1190, "r" out2D.1191, "r" out3D.1192:"b6", "f15
", "f14", "f13", "f12", "f11", "f10", "f9", "f8", "f7", "f6", "p15", "p14",
"p13", "p12", "p11", "p10", "p9", "p8", "p7", "p6", "
r31", "r30", "r29", "r28", "r27", "r26", "r25", "r24", "r23", "r22", "r21",
"r20", "r19", "r18", "r17", "r16", "r14", "r13", "r12
", "r11", "r9", "r3", "r2", "out7", "out6", "out5", "out4", "r10", "r8",
"memory");
return;
# SUCC: EXIT
Seems if the same reg is both input and output it is just among
STORED_SYMS, not LOADED_SYMS.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33389
