Enabling POPCNT generation for 32-bit pattern from Hacker's Delight
Pattern 1:
int Gia_WordCountOnes32c( uint32_t uword )
{
uword = (uword & 0x55555555) + ((uword>>1) & 0x55555555);
uword = (uword & 0x33333333) + ((uword>>2) & 0x33333333);
uword = (uword & 0x0f0f0f0f) + ((uword>>4) & 0x0f0f0f0f);
uword = (uword & 0x00ff00ff) + ((uword>>8) & 0x00ff00ff);
return (uword & 0x0000ffff) + (uword>>16);
or
return (uword & 0x0000FFFF) + ((uword >> 16) & 0x0000FFFF);
}
Pattern 2:
int pop(unsigned x) {
x = x - ((x >> 1) & 0x55555555);
x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
x = (x + (x >> 4)) & 0x0F0F0F0F;
x = x + (x >> 8);
x = x + (x >> 16);
return x & 0x0000003F;
}
Pattern 3:
int pop(unsigned x) {
x = x - ((x >> 1) & 0x55555555);
x = x - 3*((x >> 2) & 0x33333333)
x = (x + (x >> 4)) & 0x0F0F0F0F;
x = x + (x >> 8);
x = x + (x >> 16);
return x & 0x0000003F;
}
gcc/ChangeLog:
* match.pd: Add new popcount pattern variants from Hacker's Delight.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/popcount7.c: New test.
* gcc.dg/tree-ssa/popcount7_2.c: New test.
* gcc.dg/tree-ssa/popcount8.c: New test.
* gcc.dg/tree-ssa/popcount9.c: New test.
---
[Public]
Hi Richard,
The following changes were made in patch v3 based on your comments.
- Match only 32-bit unsigned types, not 16???32 with shifted masks.
- Use compare_tree_int for all constant checks.
- Merged the extra #if GIMPLE into the existing popcount block.
> -----Original Message-----
> From: Richard Biener <[email protected]>
> Sent: Monday, May 4, 2026 7:36 PM
> To: Roy, Reshma <[email protected]>
> Cc: [email protected]; Kumar, Venkataramanan
> <[email protected]>
> Subject: Re: [PATCH v2] Enabling POPCNT generation for 32-bit patterns.
>
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
>
>
> On Mon, 4 May 2026, Reshma Roy wrote:
>
> > Enabling POPCNT generation for 32-bit pattern from Hacker's Delight
> >
> > Pattern 1:
> > int Gia_WordCountOnes32c( uint32_t uword ) {
> > uword = (uword & 0x55555555) + ((uword>>1) & 0x55555555);
> > uword = (uword & 0x33333333) + ((uword>>2) & 0x33333333);
> > uword = (uword & 0x0f0f0f0f) + ((uword>>4) & 0x0f0f0f0f);
> > uword = (uword & 0x00ff00ff) + ((uword>>8) & 0x00ff00ff);
> > return (uword & 0x0000ffff) + (uword>>16);
> > or
> > return (uword & 0x0000FFFF) + ((uword >> 16) & 0x0000FFFF); }
> >
> > Pattern 2:
> > int pop(unsigned x) {
> > x = x - ((x >> 1) & 0x55555555);
> > x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
> > x = (x + (x >> 4)) & 0x0F0F0F0F;
> > x = x + (x >> 8);
> > x = x + (x >> 16);
> > return x & 0x0000003F;
> > }
> >
> > Pattern 3:
> > int pop(unsigned x) {
> > x = x - ((x >> 1) & 0x55555555);
> > x = x - 3*((x >> 2) & 0x33333333)
> > x = (x + (x >> 4)) & 0x0F0F0F0F;
> > x = x + (x >> 8);
> > x = x + (x >> 16);
> > return x & 0x0000003F;
> > }
> >
> > gcc/ChangeLog:
> >
> > * match.pd: Add new popcount pattern variants from Hacker's Delight.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * gcc.dg/tree-ssa/popcount7.c: New test.
> > * gcc.dg/tree-ssa/popcount7_2.c: New test.
> > * gcc.dg/tree-ssa/popcount8.c: New test.
> > * gcc.dg/tree-ssa/popcount9.c: New test.
> >
> > ---
> >
> > [Public]
> >
> > Hi Richard,
> >
> > I have rebased this patch and am reposting it now after the release.
> > Please let
> me know if you have any further feedback.
> >
> > Bootstrapped and tested on x86.
> >
> > Thank You,
> > Reshma Roy
> >
> >
> > gcc/match.pd | 187 ++++++++++++++++++++
> > gcc/testsuite/gcc.dg/tree-ssa/popcount7.c | 23 +++
> > gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c | 23 +++
> > gcc/testsuite/gcc.dg/tree-ssa/popcount8.c | 22 +++
> > gcc/testsuite/gcc.dg/tree-ssa/popcount9.c | 22 +++
> > 5 files changed, 277 insertions(+)
> > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
> > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
> > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
> > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
> >
> > diff --git a/gcc/match.pd b/gcc/match.pd index
> > 7db8ce7580f..d36dfefcd07 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -11167,6 +11167,193 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > (plus (CTZ:type (convert:utype @0)) { build_one_cst (type); }))))
> > #endif
> >
> > +#if GIMPLE
> > +/* To recognize the popcnt pattern for 32-bit from Hacker's Delight
> > + int Gia_WordCountOnes32c ( uint32_t uword)
> > + {
> > + uword = (uword & 0x55555555) + ((uword>>1) & 0x55555555);
> > + uword = (uword & 0x33333333) + ((uword>>2) & 0x33333333);
> > + uword = (uword & 0x0f0f0f0f) + ((uword>>4) & 0x0f0f0f0f);
> > + uword = (uword & 0x00ff00ff) + ((uword>>8) & 0x00ff00ff);
> > + return (uword & 0x0000ffff) + (uword>>16);
> > + or
> > + return (uword & 0x0000ffff) + ((uword>>16) & 0x0000ffff);
> > + }
> > +*/
> > +
> > + (simplify
> > + (plus:c
> > + (bit_and @step_4 INTEGER_CST@9)
> > + (rshift
> > + (plus:c@step4
> > + (bit_and @step3 INTEGER_CST@7)
> > + (bit_and
> > + (rshift
> > + (plus:c@step3
> > + (bit_and @step2 INTEGER_CST@5)
> > + (bit_and
> > + (rshift
> > + (plus:c@step2
> > + (bit_and @step1 INTEGER_CST@3)
> > + (bit_and
> > + (rshift
> > + (plus:c@step1
> > + (bit_and @0 INTEGER_CST@1)
> > + (bit_and (rshift @0 INTEGER_CST@2) @1))
> > + INTEGER_CST@4)
> > + INTEGER_CST@3))
> > + INTEGER_CST@6)
> > + INTEGER_CST@5))
> > + INTEGER_CST@8)
> > + INTEGER_CST@7))
> > + INTEGER_CST@10))
> > + (with {
> > + unsigned prec = TYPE_PRECISION (type);
> > + int shift = prec & 31 ;
> > + unsigned HOST_WIDE_INT c1 = HOST_WIDE_INT_UC (0x55555555) >>
> shift;
> > + unsigned HOST_WIDE_INT c2 = HOST_WIDE_INT_UC (0x33333333) >>
> shift;
> > + unsigned HOST_WIDE_INT c3 = HOST_WIDE_INT_UC (0x0F0F0F0F) >>
> shift;
> > + unsigned HOST_WIDE_INT c4 = HOST_WIDE_INT_UC (0x00FF00FF) >>
> shift;
> > + unsigned HOST_WIDE_INT c5 = HOST_WIDE_INT_UC (0x0000FFFF) >>
> shift;
> > + }
> > + (if (prec >= 16
> > + && prec <= 32
>
> Does this really work for prec != 32? Similar below.
No. Hence the patch is updated for 32 bit alone.
>
> > + && pow2p_hwi (prec)
> > + && TYPE_UNSIGNED (type)
> > + && integer_onep (@2)
> > + && wi::to_widest (@4) == 2
> > + && wi::to_widest (@6) == 4
> > + && wi::to_widest (@8) == 8
> > + && wi::to_widest (@10) == 16
> > + && tree_to_uhwi (@1) == c1
> > + && tree_to_uhwi (@3) == c2
> > + && tree_to_uhwi (@5) == c3
> > + && tree_to_uhwi (@7) == c4
> > + && tree_to_uhwi (@9) == c5)
> > + (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
> > + OPTIMIZE_FOR_BOTH))
> > + (convert (IFN_POPCOUNT:type @0)))))) #endif #if GIMPLE
>
> Please merge the #ifs, specifically insert the new patterns in the existing
> block doing
> 64- and 32-bits branchless implementations of popcount.
Done.
>
> > +/*To recognize the popcnt pattern for 32-bit from Hacker's Delight
> > +int pop (unsigned x) { x = x - ((x >> 1) & 0x55555555); x = (x &
> > +0x33333333) + ((x >> 2) & 0x33333333); x = x - 3*((x >> 2) &
> > +0x33333333); x = (x + (x >> 4)) & 0x0F0F0F0F; x = x + (x >> 8); x = x
> > ++ (x >> 16); return x & 0x0000003F } */ (simplify (bit_and
> > + (plus
> > + (rshift @step4 INTEGER_CST@10)
> > + (plus:c@step4
> > + (rshift @step3 INTEGER_CST@8)
> > + (bit_and@step3
> > + (plus
> > + (rshift @step2 INTEGER_CST@6)
> > + (plus:c@step2
> > + (bit_and @step1 INTEGER_CST@3)
> > + (bit_and
> > + (rshift
> > + (minus@step1
> > + @0
> > + (bit_and (rshift @0 INTEGER_CST@2)
> > INTEGER_CST@1))
> > + INTEGER_CST@4)
> > + INTEGER_CST@3)))
> > + INTEGER_CST@5)))
> > + INTEGER_CST@7)
> > + (with {
> > + unsigned prec = TYPE_PRECISION (type);
> > + int shift = prec & 31 ;
> > + unsigned HOST_WIDE_INT c1 = HOST_WIDE_INT_UC (0x55555555) >>
> shift;
> > + unsigned HOST_WIDE_INT c2 = HOST_WIDE_INT_UC (0x33333333) >>
> shift;
> > + unsigned HOST_WIDE_INT c3 = HOST_WIDE_INT_UC (0x0F0F0F0F) >>
> shift;
> > + unsigned HOST_WIDE_INT c4 = HOST_WIDE_INT_UC (0x0000003F) >>
> shift;
> > + }
> > + (if (prec >= 16
> > + && prec <= 32
> > + && pow2p_hwi (prec)
> > + && TYPE_UNSIGNED (type)
> > + && integer_onep (@2)
>
> I think you can use compare_tree_int (@2, 1) and similar for all of the
> checks. At
> least they should all use the same way of testing for a constant, not three
> different
> ones.
Updated the patch to use compare_tree_int() for all the checks.
>
> > + && wi::to_widest (@4) == 2
> > + && wi::to_widest (@6) == 4
> > + && wi::to_widest (@8) == 8
> > + && wi::to_widest (@10) == 16
> > + && tree_to_uhwi (@1) == c1
> > + && tree_to_uhwi (@3) == c2
> > + && tree_to_uhwi (@5) == c3
> > + && tree_to_uhwi (@7) == c4)
> > + (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
> > + OPTIMIZE_FOR_BOTH))
> > + (convert (IFN_POPCOUNT:type @0)))))) #endif #if GIMPLE
> > +
> > +/*To recognize the popcnt pattern for 32-bit from Hacker's Delight
> > +/*int pop (unsigned x) {
> > + x = x - ((x >> 1) & 0x55555555);
> > + x = x - 3*((x >> 2) & 0x33333333)
> > + x = (x + (x >> 4)) & 0x0F0F0F0F;
> > + x = x + (x >> 8);
> > + x = x + (x >> 16);
> > + return x & 0x0000003F;
> > +}
> > +*/
> > +(simplify
> > + (bit_and
> > + (plus
> > + (rshift @step4 INTEGER_CST@10)
> > + (plus:c@step4
> > + (rshift @step3 INTEGER_CST@8)
> > + (bit_and@step3
> > + (plus
> > + (rshift @step2 INTEGER_CST@6)
> > + (minus@step2
> > + @step1
> > + (mult:c
> > + (bit_and
> > + (rshift
> > + (minus@step1
> > + @0
> > + (bit_and (rshift @0 INTEGER_CST@2)
> > INTEGER_CST@1))
> > + INTEGER_CST@4)
> > + INTEGER_CST@3)
> > + INTEGER_CST@11)))
> > + INTEGER_CST@5)))
> > + INTEGER_CST@7)
> > + (with {
> > + unsigned prec = TYPE_PRECISION (type);
> > + int shift = prec & 31 ;
> > + unsigned HOST_WIDE_INT c1 = HOST_WIDE_INT_UC (0x55555555) >>
> shift;
> > + unsigned HOST_WIDE_INT c2 = HOST_WIDE_INT_UC (0x33333333) >>
> shift;
> > + unsigned HOST_WIDE_INT c3 = HOST_WIDE_INT_UC (0x0F0F0F0F) >>
> shift;
> > + unsigned HOST_WIDE_INT c4 = HOST_WIDE_INT_UC (0x0000003F) >>
> shift;
> > + }
> > + (if (prec >= 16
> > + && prec <= 32
> > + && pow2p_hwi (prec)
> > + && TYPE_UNSIGNED (type)
> > + && integer_onep (@2)
> > + && wi::to_widest (@4) == 2
> > + && wi::to_widest (@6) == 4
> > + && wi::to_widest (@8) == 8
> > + && wi::to_widest (@10) == 16
> > + && wi::to_widest (@11) == 3
> > + && tree_to_uhwi (@1) == c1
> > + && tree_to_uhwi (@3) == c2
> > + && tree_to_uhwi (@5) == c3
> > + && tree_to_uhwi (@7) == c4)
> > + (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
> > + OPTIMIZE_FOR_BOTH))
> > + (convert (IFN_POPCOUNT:type @0)))))) #endif
> > +
> > (for ffs (FFS)
> > /* __builtin_ffs (X) == 0 -> X == 0.
> > __builtin_ffs (X) == 6 -> (X & 63) == 32. */ diff --git
> > a/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
> > new file mode 100644
> > index 00000000000..c70837fc53b
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
> > @@ -0,0 +1,23 @@
> > +/* { dg-do compile } */
> > +/* { dg-require-effective-target popcount } */
> > +/* { dg-require-effective-target int32plus } */
> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > +
> > +const unsigned m1 = 0x55555555UL;
> > +const unsigned m2 = 0x33333333UL;
> > +const unsigned m3 = 0x0F0F0F0FUL;
> > +const unsigned m4 = 0x00FF00FFUL;
> > +const unsigned m5 = 0x0000FFFFUL;
> > +
> > +int Gia_WordCountOnes32c( unsigned uword ) {
> > + uword = (uword & m1) + ((uword>>1) & m1);
> > + uword = (uword & m2) + ((uword>>2) & m2);
> > + uword = (uword & m3) + ((uword>>4) & m3);
> > + uword = (uword & m4) + ((uword>>8) & m4);
> > + return (uword & m5) + (uword>>16); }
> > +
> > +/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } }
> > +*/
> > +
> > +
> > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
> > new file mode 100644
> > index 00000000000..fc6c23b411b
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
> > @@ -0,0 +1,23 @@
> > +/* { dg-do compile } */
> > +/* { dg-require-effective-target popcount } */
> > +/* { dg-require-effective-target int32plus } */
> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > +
> > +const unsigned m1 = 0x55555555UL;
> > +const unsigned m2 = 0x33333333UL;
> > +const unsigned m3 = 0x0F0F0F0FUL;
> > +const unsigned m4 = 0x00FF00FFUL;
> > +const unsigned m5 = 0x0000FFFFUL;
> > +
> > +int Gia_WordCountOnes32c( unsigned uword ) {
> > + uword = (uword & m1) + ((uword>>1) & m1);
> > + uword = (uword & m2) + ((uword>>2) & m2);
> > + uword = (uword & m3) + ((uword>>4) & m3);
> > + uword = (uword & m4) + ((uword>>8) & m4);
> > + return (uword & m5) + ((uword>>16) & m5); }
> > +
> > +/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } }
> > +*/
> > +
> > +
> > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
> > new file mode 100644
> > index 00000000000..5a12e6892aa
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
> > @@ -0,0 +1,22 @@
> > +/* { dg-do compile } */
> > +/* { dg-require-effective-target popcount } */
> > +/* { dg-require-effective-target int32plus } */
> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > +
> > +const unsigned m1 = 0x55555555UL;
> > +const unsigned m2 = 0x33333333UL;
> > +const unsigned m3 = 0x0F0F0F0FUL;
> > +const unsigned m4 = 0x0000003F;
> > +
> > +int pop32c(unsigned x) {
> > + x = x - ((x >> 1) & m1);
> > + x = (x & m2) + ((x >> 2) & m2);
> > + x = (x + (x >> 4)) & m3;
> > + x = x + (x >> 8);
> > + x = x + (x >> 16);
> > + return x & m4;
> > +}
> > +
> > +/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } }
> > +*/
> > +
> > +
> > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
> > new file mode 100644
> > index 00000000000..4fb08d34984
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
> > @@ -0,0 +1,22 @@
> > +/* { dg-do compile } */
> > +/* { dg-require-effective-target popcount } */
> > +/* { dg-require-effective-target int32plus } */
> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > +
> > +const unsigned m1 = 0x55555555UL;
> > +const unsigned m2 = 0x33333333UL;
> > +const unsigned m3 = 0x0F0F0F0FUL;
> > +const unsigned m4 = 0x0000003F;
> > +
> > +int popc(unsigned x) {
> > + x = x - ((x >> 1) & m1);
> > + x = x - 3*((x >> 2) & m2);
> > + x = (x + (x >> 4)) & m3;
> > + x = x + (x >> 8);
> > + x = x + (x >> 16);
> > + return x & m4;
> > +}
> > +
> > +/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } }
> > +*/
> > +
> > +
> >
>
> --
> Richard Biener <[email protected]>
> SUSE Software Solutions Germany GmbH,
> Frankenstrasse 146, 90461 Nuernberg, Germany;
> GF: Jochen Jaser, Andrew McDonald, Werner Knoblich; (HRB 36809, AG
> Nuernberg)
Thank You,
Reshma Roy
gcc/match.pd | 160 ++++++++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/popcount7.c | 23 +++
gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c | 23 +++
gcc/testsuite/gcc.dg/tree-ssa/popcount8.c | 22 +++
gcc/testsuite/gcc.dg/tree-ssa/popcount9.c | 22 +++
5 files changed, 250 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 7db8ce7580f..212ba6a189e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -11165,6 +11165,166 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
OPTIMIZE_FOR_SPEED))
(with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
(plus (CTZ:type (convert:utype @0)) { build_one_cst (type); }))))
+
+/* To recognize the popcnt pattern for 32-bit from Hacker's Delight
+ int Gia_WordCountOnes32c ( uint32_t uword)
+ {
+ uword = (uword & 0x55555555) + ((uword>>1) & 0x55555555);
+ uword = (uword & 0x33333333) + ((uword>>2) & 0x33333333);
+ uword = (uword & 0x0f0f0f0f) + ((uword>>4) & 0x0f0f0f0f);
+ uword = (uword & 0x00ff00ff) + ((uword>>8) & 0x00ff00ff);
+ return (uword & 0x0000ffff) + (uword>>16);
+ or
+ return (uword & 0x0000ffff) + ((uword>>16) & 0x0000ffff);
+ }
+*/
+
+ (simplify
+ (plus:c
+ (bit_and @step_4 INTEGER_CST@9)
+ (rshift
+ (plus:c@step4
+ (bit_and @step3 INTEGER_CST@7)
+ (bit_and
+ (rshift
+ (plus:c@step3
+ (bit_and @step2 INTEGER_CST@5)
+ (bit_and
+ (rshift
+ (plus:c@step2
+ (bit_and @step1 INTEGER_CST@3)
+ (bit_and
+ (rshift
+ (plus:c@step1
+ (bit_and @0 INTEGER_CST@1)
+ (bit_and (rshift @0 INTEGER_CST@2) @1))
+ INTEGER_CST@4)
+ INTEGER_CST@3))
+ INTEGER_CST@6)
+ INTEGER_CST@5))
+ INTEGER_CST@8)
+ INTEGER_CST@7))
+ INTEGER_CST@10))
+ (with {
+ unsigned prec = TYPE_PRECISION (type);
+ }
+ (if (prec == 32
+ && TYPE_UNSIGNED (type)
+ && compare_tree_int (@2, 1) == 0
+ && compare_tree_int (@4, 2) == 0
+ && compare_tree_int (@6, 4) == 0
+ && compare_tree_int (@8, 8) == 0
+ && compare_tree_int (@10, 16) == 0
+ && compare_tree_int (@1, 0x55555555) == 0
+ && compare_tree_int (@3, 0x33333333) == 0
+ && compare_tree_int (@5, 0x0F0F0F0F) == 0
+ && compare_tree_int (@7, 0x00FF00FF) == 0
+ && compare_tree_int (@9, 0x0000FFFF) == 0)
+ (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
+ OPTIMIZE_FOR_BOTH))
+ (convert (IFN_POPCOUNT:type @0))))))
+
+/*To recognize the popcnt pattern for 32-bit from Hacker's Delight
+int pop (unsigned x)
+{
+x = x - ((x >> 1) & 0x55555555);
+x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
+x = x - 3*((x >> 2) & 0x33333333);
+x = (x + (x >> 4)) & 0x0F0F0F0F;
+x = x + (x >> 8);
+x = x + (x >> 16);
+return x & 0x0000003F
+}
+*/
+(simplify
+ (bit_and
+ (plus
+ (rshift @step4 INTEGER_CST@10)
+ (plus:c@step4
+ (rshift @step3 INTEGER_CST@8)
+ (bit_and@step3
+ (plus
+ (rshift @step2 INTEGER_CST@6)
+ (plus:c@step2
+ (bit_and @step1 INTEGER_CST@3)
+ (bit_and
+ (rshift
+ (minus@step1
+ @0
+ (bit_and (rshift @0 INTEGER_CST@2) INTEGER_CST@1))
+ INTEGER_CST@4)
+ INTEGER_CST@3)))
+ INTEGER_CST@5)))
+ INTEGER_CST@7)
+ (with {
+ unsigned prec = TYPE_PRECISION (type);
+ }
+ (if (prec == 32
+ && TYPE_UNSIGNED (type)
+ && compare_tree_int (@2, 1) == 0
+ && compare_tree_int (@4, 2) == 0
+ && compare_tree_int (@6, 4) == 0
+ && compare_tree_int (@8, 8) == 0
+ && compare_tree_int (@10, 16) == 0
+ && compare_tree_int (@1, 0x55555555) == 0
+ && compare_tree_int (@3, 0x33333333) == 0
+ && compare_tree_int (@5, 0x0F0F0F0F) == 0
+ && compare_tree_int (@7, 0x0000003F) == 0)
+ (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
+ OPTIMIZE_FOR_BOTH))
+ (convert (IFN_POPCOUNT:type @0))))))
+
+/*To recognize the popcnt pattern for 32-bit from Hacker's Delight
+/*int pop (unsigned x)
+{
+ x = x - ((x >> 1) & 0x55555555);
+ x = x - 3*((x >> 2) & 0x33333333)
+ x = (x + (x >> 4)) & 0x0F0F0F0F;
+ x = x + (x >> 8);
+ x = x + (x >> 16);
+ return x & 0x0000003F;
+}
+*/
+(simplify
+ (bit_and
+ (plus
+ (rshift @step4 INTEGER_CST@10)
+ (plus:c@step4
+ (rshift @step3 INTEGER_CST@8)
+ (bit_and@step3
+ (plus
+ (rshift @step2 INTEGER_CST@6)
+ (minus@step2
+ @step1
+ (mult:c
+ (bit_and
+ (rshift
+ (minus@step1
+ @0
+ (bit_and (rshift @0 INTEGER_CST@2) INTEGER_CST@1))
+ INTEGER_CST@4)
+ INTEGER_CST@3)
+ INTEGER_CST@11)))
+ INTEGER_CST@5)))
+ INTEGER_CST@7)
+ (with {
+ unsigned prec = TYPE_PRECISION (type);
+ }
+ (if (prec == 32
+ && TYPE_UNSIGNED (type)
+ && compare_tree_int (@2, 1) == 0
+ && compare_tree_int (@4, 2) == 0
+ && compare_tree_int (@6, 4) == 0
+ && compare_tree_int (@8, 8) == 0
+ && compare_tree_int (@10, 16) == 0
+ && compare_tree_int (@11, 3) == 0
+ && compare_tree_int (@1, 0x55555555) == 0
+ && compare_tree_int (@3, 0x33333333) == 0
+ && compare_tree_int (@5, 0x0F0F0F0F) == 0
+ && compare_tree_int (@5, 0x0F0F0F0F) == 0)
+ (if (direct_internal_fn_supported_p (IFN_POPCOUNT, type,
+ OPTIMIZE_FOR_BOTH))
+ (convert (IFN_POPCOUNT:type @0))))))
#endif
(for ffs (FFS)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
b/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
new file mode 100644
index 00000000000..c70837fc53b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount7.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target popcount } */
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+const unsigned m1 = 0x55555555UL;
+const unsigned m2 = 0x33333333UL;
+const unsigned m3 = 0x0F0F0F0FUL;
+const unsigned m4 = 0x00FF00FFUL;
+const unsigned m5 = 0x0000FFFFUL;
+
+int Gia_WordCountOnes32c( unsigned uword )
+{
+ uword = (uword & m1) + ((uword>>1) & m1);
+ uword = (uword & m2) + ((uword>>2) & m2);
+ uword = (uword & m3) + ((uword>>4) & m3);
+ uword = (uword & m4) + ((uword>>8) & m4);
+ return (uword & m5) + (uword>>16);
+}
+
+/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } } */
+
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
b/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
new file mode 100644
index 00000000000..fc6c23b411b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount7_2.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target popcount } */
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+const unsigned m1 = 0x55555555UL;
+const unsigned m2 = 0x33333333UL;
+const unsigned m3 = 0x0F0F0F0FUL;
+const unsigned m4 = 0x00FF00FFUL;
+const unsigned m5 = 0x0000FFFFUL;
+
+int Gia_WordCountOnes32c( unsigned uword )
+{
+ uword = (uword & m1) + ((uword>>1) & m1);
+ uword = (uword & m2) + ((uword>>2) & m2);
+ uword = (uword & m3) + ((uword>>4) & m3);
+ uword = (uword & m4) + ((uword>>8) & m4);
+ return (uword & m5) + ((uword>>16) & m5);
+}
+
+/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } } */
+
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
b/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
new file mode 100644
index 00000000000..5a12e6892aa
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount8.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target popcount } */
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+const unsigned m1 = 0x55555555UL;
+const unsigned m2 = 0x33333333UL;
+const unsigned m3 = 0x0F0F0F0FUL;
+const unsigned m4 = 0x0000003F;
+
+int pop32c(unsigned x) {
+ x = x - ((x >> 1) & m1);
+ x = (x & m2) + ((x >> 2) & m2);
+ x = (x + (x >> 4)) & m3;
+ x = x + (x >> 8);
+ x = x + (x >> 16);
+ return x & m4;
+}
+
+/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } } */
+
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
b/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
new file mode 100644
index 00000000000..4fb08d34984
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount9.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target popcount } */
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+const unsigned m1 = 0x55555555UL;
+const unsigned m2 = 0x33333333UL;
+const unsigned m3 = 0x0F0F0F0FUL;
+const unsigned m4 = 0x0000003F;
+
+int popc(unsigned x) {
+ x = x - ((x >> 1) & m1);
+ x = x - 3*((x >> 2) & m2);
+ x = (x + (x >> 4)) & m3;
+ x = x + (x >> 8);
+ x = x + (x >> 16);
+ return x & m4;
+}
+
+/* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } } */
+
+
--
2.34.1
