Hi!
The following testcase started to ICE when .POPCOUNT matching has been added
to match.pd; we had __builtin_popcount*, but nothing would use the
popcounthi2 expander before.
The problem is that the popcounthi2_z196 expander doesn't emit valid RTL:
error: unrecognizable insn:
(insn 138 137 139 27 (set (reg:SI 190)
(ashift:SI (reg:HI 95 [ _105 ])
(const_int 8 [0x8]))) -1
(nil))
during RTL pass: vregs
The following patch is an attempt to fix that, furthermore I've tried to
slightly simplify it as well, it makes no sense to me to perform
(x + (x << 8)) >> 8 when we need to either zero extend or mask the result
at the end in order to avoid bits from above HImode to affect it, when we
can do
(x + (x >> 8)) & 0xff (or zero extension).
Bootstrapped/regtested on s390x-linux, ok for trunk?
2020-02-01 Jakub jelinek <ja...@redhat.com>
PR target/93533
* config/s390/s390.md (popcounthi2_z196): Fix up expander to emit
valid RTL to sum up the lowest and second lowest bytes of the popcnt
result.
--- gcc/config/s390/s390.md.jj 2020-01-12 11:54:36.412413424 +0100
+++ gcc/config/s390/s390.md 2020-02-01 13:34:21.671431689 +0100
@@ -11670,21 +11670,28 @@ (define_expand "popcountsi2"
})
(define_expand "popcounthi2_z196"
- [; popcnt op0, op1
- (parallel [(set (match_operand:HI 0 "register_operand" "")
+ [; popcnt op2, op1
+ (parallel [(set (match_dup 2)
(unspec:HI [(match_operand:HI 1 "register_operand")]
UNSPEC_POPCNT))
(clobber (reg:CC CC_REGNUM))])
- ; sllk op2, op0, 8
- (set (match_dup 2)
- (ashift:SI (match_dup 0) (const_int 8)))
- ; ar op0, op2
- (parallel [(set (match_dup 0) (plus:SI (match_dup 0) (match_dup 2)))
+ ; lr op3, op2
+ (set (match_dup 3) (subreg:SI (match_dup 2) 0))
+ ; srl op4, op3, 8
+ (set (match_dup 4) (lshiftrt:SI (match_dup 3) (const_int 8)))
+ ; ar op3, op4
+ (parallel [(set (match_dup 3) (plus:SI (match_dup 3) (match_dup 4)))
(clobber (reg:CC CC_REGNUM))])
- ; srl op0, op0, 8
- (set (match_dup 0) (lshiftrt:HI (match_dup 0) (const_int 8)))]
+ ; llgc op0, op3
+ (parallel [(set (match_operand:HI 0 "register_operand" "")
+ (and:HI (subreg:HI (match_dup 3) 2) (const_int 255)))
+ (clobber (reg:CC CC_REGNUM))])]
"TARGET_Z196"
- "operands[2] = gen_reg_rtx (SImode);")
+{
+ operands[2] = gen_reg_rtx (HImode);
+ operands[3] = gen_reg_rtx (SImode);
+ operands[4] = gen_reg_rtx (SImode);
+})
(define_expand "popcounthi2"
[(set (match_dup 2)
--- gcc/testsuite/gcc.c-torture/compile/pr93533.c.jj 2020-02-01
13:44:16.296681108 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr93533.c 2020-02-01
13:43:52.034038073 +0100
@@ -0,0 +1,9 @@
+/* PR target/93533 */
+
+unsigned
+foo (unsigned short a)
+{
+ a = a - (a >> 1 & 21845);
+ a = (a & 13107) + (a >> 2 & 13107);
+ return (unsigned short) ((a + (a >> 4) & 3855) * 257) >> 8;
+}
--- gcc/testsuite/gcc.target/s390/pr93533.c.jj 2020-02-01 13:45:41.433428499
+0100
+++ gcc/testsuite/gcc.target/s390/pr93533.c 2020-02-01 13:45:32.984552824
+0100
@@ -0,0 +1,5 @@
+/* PR target/93533 */
+/* { dg-do compile } */
+/* { dg-options "-march=z196 -O2" } */
+
+#include "../../gcc.c-torture/compile/pr93533.c"
Jakub
