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arm.c (arm_rtx_costs): Improve for xscale multiply. 

* config/arm/arm.c (arm_rtx_costs): Improve for xscale multiply.
* testsuite/gcc.dg/arm-g2.c: New test.

From-SVN: r74149
This commit is contained in:
James Lemke 2003-12-02 02:17:18 +00:00 committed by James Lemke
parent d9e7c8e3c3
commit e3b661203f
4 changed files with 55 additions and 6 deletions
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4
gcc/ChangeLog
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@ -1,3 +1,7 @@
2003-12-01 James Lemke <jim@wasabisystems.com>
* config/arm/arm.c (arm_rtx_costs): Improve for xscale multiply.
2003-12-01 Roger Sayle <roger@eyesopen.com>
PR optimization/11634

34
gcc/config/arm/arm.c
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@ -3389,19 +3389,41 @@ arm_rtx_costs_1 (rtx x, enum rtx_code code, enum rtx_code outer)
{
unsigned HOST_WIDE_INT i = (INTVAL (XEXP (x, 1))
& (unsigned HOST_WIDE_INT) 0xffffffff);
int add_cost = const_ok_for_arm (i) ? 4 : 8;
int j;
int cost, const_ok = const_ok_for_arm (i);
int j, booth_unit_size;
if (arm_tune_xscale)
{
unsigned HOST_WIDE_INT masked_const;
/* The cost will be related to two insns.
First a load of the constant (MOV or LDR), then a multiply. */
cost = 2;
if (! const_ok)
cost += 1; /* LDR is probably more expensive because
of longer result latency. */
masked_const = i & 0xffff8000;
if (masked_const != 0 && masked_const != 0xffff8000)
{
masked_const = i & 0xf8000000;
if (masked_const == 0 || masked_const == 0xf8000000)
cost += 1;
else
cost += 2;
}
return cost;
}
/* Tune as appropriate. */
int booth_unit_size = ((tune_flags & FL_FAST_MULT) ? 8 : 2);
cost = const_ok ? 4 : 8;
booth_unit_size = ((tune_flags & FL_FAST_MULT) ? 8 : 2);
for (j = 0; i && j < 32; j += booth_unit_size)
{
i >>= booth_unit_size;
add_cost += 2;
cost += 2;
}
return add_cost;
return cost;
}
return (((tune_flags & FL_FAST_MULT) ? 8 : 30)

4
gcc/testsuite/ChangeLog
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@ -1,3 +1,7 @@
2003-12-01 James Lemke <jim@wasabisystems.com>
* gcc.dg/arm-g2.c: New test.
2003-12-01 Roger Sayle <roger@eyesopen.com>
PR optimization/11634

19
gcc/testsuite/gcc.dg/arm-g2.c Normal file
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@ -0,0 +1,19 @@
/* Verify that hardware multiply is preferred on XScale. */
/* { dg-do compile { target xscale*-*-* } } */
/* { dg-options "-mcpu=xscale -O2" } */
/* Brett Gaines' test case. */
unsigned BCPL(unsigned) __attribute__ ((naked));
unsigned BCPL(unsigned seed)
{
/* Best code would be:
ldr r1, =2147001325
ldr r2, =715136305
mla r0, r1, r0, r2
mov pc, lr */
return seed * 2147001325U + 715136305U;
}
/* We want to suppress running for -mthumb but not for -mthumb-interwork. */
/* { dg-final { global compiler_flags; if ![string match "*-mthumb *" $compiler_flags] { scan-assembler "mla\[ ].*" } } } */