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authorH.J. Lu <hjl.tools@gmail.com>2021-08-01 09:55:33 -0700
committerH.J. Lu <hjl.tools@gmail.com>2021-08-01 13:32:55 -0700
commit6f0c43e97825ee54e3779afbedcd0def12443001 (patch)
tree96c88229bdbe88003206abe51a0803d7d5f99843
parent8dd16447343890091874c9f588a7fea8c840cf77 (diff)
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i386: Improve SImode constant - __builtin_clzll for -mno-lzcnt
Add a zero_extend patten for bsr_rex64_1 and use it to split SImode constant - __builtin_clzll to avoid unncessary zero_extend. gcc/ PR target/78103 * config/i386/i386.md (bsr_rex64_1_zext): New. (combine splitter for constant - clzll): Replace gen_bsr_rex64_1 with gen_bsr_rex64_1_zext. gcc/testsuite/ PR target/78103 * gcc.target/i386/pr78103-2.c: Also scan incl. * gcc.target/i386/pr78103-3.c: Scan leal|addl|incl for x32. Also scan incq.
-rw-r--r--gcc/config/i386/i386.md17
-rw-r--r--gcc/testsuite/gcc.target/i386/pr78103-2.c2
-rw-r--r--gcc/testsuite/gcc.target/i386/pr78103-3.c3
3 files changed, 19 insertions, 3 deletions
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index c9787d7..0c23ddb 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -14796,6 +14796,21 @@
(set_attr "znver1_decode" "vector")
(set_attr "mode" "DI")])
+(define_insn "bsr_rex64_1_zext"
+ [(set (match_operand:DI 0 "register_operand" "=r")
+ (zero_extend:DI
+ (minus:SI (const_int 63)
+ (subreg:SI
+ (clz:DI (match_operand:DI 1 "nonimmediate_operand" "rm"))
+ 0))))
+ (clobber (reg:CC FLAGS_REG))]
+ "!TARGET_LZCNT && TARGET_64BIT"
+ "bsr{q}\t{%1, %0|%0, %1}"
+ [(set_attr "type" "alu1")
+ (set_attr "prefix_0f" "1")
+ (set_attr "znver1_decode" "vector")
+ (set_attr "mode" "DI")])
+
(define_insn "bsr"
[(set (reg:CCZ FLAGS_REG)
(compare:CCZ (match_operand:SI 1 "nonimmediate_operand" "rm")
@@ -14907,7 +14922,7 @@
operands[5] = lowpart_subreg (SImode, operands[3], DImode);
if (INTVAL (operands[2]) == 63)
{
- emit_insn (gen_bsr_rex64_1 (operands[3], operands[1]));
+ emit_insn (gen_bsr_rex64_1_zext (operands[3], operands[1]));
emit_move_insn (operands[0], operands[5]);
DONE;
}
diff --git a/gcc/testsuite/gcc.target/i386/pr78103-2.c b/gcc/testsuite/gcc.target/i386/pr78103-2.c
index b352338..30f7f98 100644
--- a/gcc/testsuite/gcc.target/i386/pr78103-2.c
+++ b/gcc/testsuite/gcc.target/i386/pr78103-2.c
@@ -4,7 +4,7 @@
/* { dg-final { scan-assembler-not {\mmovl\M} } } */
/* { dg-final { scan-assembler-not {\mxor[lq]\M} } } */
/* { dg-final { scan-assembler-not {\msubl\M} } } */
-/* { dg-final { scan-assembler {\m(leal|addl)\M} } } */
+/* { dg-final { scan-assembler {\m(leal|addl|incl)\M} } } */
unsigned int
foo (unsigned int x)
diff --git a/gcc/testsuite/gcc.target/i386/pr78103-3.c b/gcc/testsuite/gcc.target/i386/pr78103-3.c
index 49a36ec..b8d8231 100644
--- a/gcc/testsuite/gcc.target/i386/pr78103-3.c
+++ b/gcc/testsuite/gcc.target/i386/pr78103-3.c
@@ -5,7 +5,8 @@
/* { dg-final { scan-assembler-not {\mmovslq\M} } } */
/* { dg-final { scan-assembler-not {\mxor[lq]\M} } } */
/* { dg-final { scan-assembler-not {\msubq\M} } } */
-/* { dg-final { scan-assembler {\m(leaq|addq)\M} } } */
+/* { dg-final { scan-assembler {\m(leaq|addq|incq)\M} { target { ! x32 } } } } */
+/* { dg-final { scan-assembler {\m(leal|addl|incl)\M} { target x32 } } } */
unsigned long long
foo (unsigned int x)