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re PR rtl-optimization/65220 (integer division in stack alignment for VLA allocation)

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PR rtl-optimization/65220
	* config/i386/i386.md (*udivmod<mode>4_pow2): New.

Co-Authored-By: Aldy Hernandez <aldyh@redhat.com>

From-SVN: r221064
This commit is contained in:
Jakub Jelinek 2015-02-27 16:01:57 +01:00 committed by Aldy Hernandez
parent 4fcfb584fe
commit 395df65e21
3 changed files with 52 additions and 0 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2015-02-26 Jakub Jelinek <jakub@redhat.com>
Aldy Hernandez <aldyh@redhat.com>
PR rtl-optimization/65220
* config/i386/i386.md (*udivmod<mode>4_pow2): New.
2015-02-27 Vladimir Makarov <vmakarov@redhat.com>
PR target/65032

26
gcc/config/i386/i386.md
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@ -7331,6 +7331,32 @@
[(set_attr "type" "multi")
(set_attr "mode" "<MODE>")])
;; Optimize division or modulo by constant power of 2, if the constant
;; materializes only after expansion.
(define_insn_and_split "*udivmod<mode>4_pow2"
[(set (match_operand:SWI48 0 "register_operand" "=r")
(udiv:SWI48 (match_operand:SWI48 2 "register_operand" "0")
(match_operand:SWI48 3 "const_int_operand" "n")))
(set (match_operand:SWI48 1 "register_operand" "=r")
(umod:SWI48 (match_dup 2) (match_dup 3)))
(clobber (reg:CC FLAGS_REG))]
"UINTVAL (operands[3]) - 2 < <MODE_SIZE> * BITS_PER_UNIT
&& (UINTVAL (operands[3]) & (UINTVAL (operands[3]) - 1)) == 0"
"#"
"&& reload_completed"
[(set (match_dup 1) (match_dup 2))
(parallel [(set (match_dup 0) (lshiftrt:<MODE> (match_dup 2) (match_dup 4)))
(clobber (reg:CC FLAGS_REG))])
(parallel [(set (match_dup 1) (and:<MODE> (match_dup 1) (match_dup 5)))
(clobber (reg:CC FLAGS_REG))])]
{
int v = exact_log2 (UINTVAL (operands[3]));
operands[4] = GEN_INT (v);
operands[5] = GEN_INT ((HOST_WIDE_INT_1U << v) - 1);
}
[(set_attr "type" "multi")
(set_attr "mode" "<MODE>")])
(define_insn "*udivmod<mode>4_noext"
[(set (match_operand:SWIM248 0 "register_operand" "=a")
(udiv:SWIM248 (match_operand:SWIM248 2 "register_operand" "0")

20
gcc/testsuite/gcc.target/i386/pr65520.c Normal file
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@ -0,0 +1,20 @@
/* PR target/65520 */
/* { dg-do compile } */
/* { dg-options "-O2" } */
int foo (void *);
void
bar (void)
{
unsigned s = 128;
while (1)
{
unsigned b[s];
if (foo (b))
break;
s *= 2;
}
}
/* { dg-final { scan-assembler-not "div\[^\n\r]*%" } } */