Changes since v1:
- Fix synthesis-15.c.
-- >8 --
Improve handling of constants where the high half can be constructed by
inverting the lower half.
gcc/ChangeLog:
* config/riscv/riscv.cc (riscv_build_integer): Detect constants
were the higher half is the lower half inverted.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/synthesis-15.c: New test.
---
gcc/config/riscv/riscv.cc | 30 +++++++++++++++++++
gcc/testsuite/gcc.target/riscv/synthesis-15.c | 26 ++++++++++++++++
2 files changed, 56 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/riscv/synthesis-15.c
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index df8a5a1c1e2..393f90bbbce 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -1341,6 +1341,36 @@ riscv_build_integer (struct riscv_integer_op *codes,
HOST_WIDE_INT value,
alt_codes[alt_cost - 1].use_uw = false;
alt_codes[alt_cost - 1].save_temporary = false;
+ memcpy (codes, alt_codes, sizeof (alt_codes));
+ cost = alt_cost;
+ }
+ }
+ }
+
+ if (cost > 5 && !bit31)
+ {
+ /* For constants where the upper half is the lower half inverted we
can flip
+ it with an xor and do a shift 32 followed by an or. */
+ if (hival == (~loval & 0xffffffff))
+ {
+ alt_cost = 3 + riscv_build_integer_1 (alt_codes,
+ sext_hwi (loval, 32), mode);
+ if (alt_cost < cost)
+ {
+ alt_codes[alt_cost - 4].save_temporary = true;
+ alt_codes[alt_cost - 3].code = XOR;
+ alt_codes[alt_cost - 3].value = -1;
+ alt_codes[alt_cost - 3].use_uw = false;
+ alt_codes[alt_cost - 3].save_temporary = false;
+ alt_codes[alt_cost - 2].code = ASHIFT;
+ alt_codes[alt_cost - 2].value = 32;
+ alt_codes[alt_cost - 2].use_uw = false;
+ alt_codes[alt_cost - 2].save_temporary = false;
+ alt_codes[alt_cost - 1].code = CONCAT;
+ alt_codes[alt_cost - 1].value = 0;
+ alt_codes[alt_cost - 1].use_uw = false;
+ alt_codes[alt_cost - 1].save_temporary = false;
+
memcpy (codes, alt_codes, sizeof (alt_codes));
cost = alt_cost;
}
diff --git a/gcc/testsuite/gcc.target/riscv/synthesis-15.c
b/gcc/testsuite/gcc.target/riscv/synthesis-15.c
new file mode 100644
index 00000000000..dc1f8b70194
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/synthesis-15.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target rv64 } */
+/* We aggressively skip as we really just need to test the basic synthesis
+ which shouldn't vary based on the optimization level. -O1 seems to work
+ and eliminates the usual sources of extraneous dead code that would throw
+ off the counts. */
+/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-O2" "-O3" "-Os" "-Oz" "-flto" } }
*/
+/* { dg-options "-march=rv64gc" } */
+
+/* Rather than test for a specific synthesis of all these constants or
+ having thousands of tests each testing one variant, we just test the
+ total number of instructions.
+
+ This isn't expected to change much and any change is worthy of a look. */
+/* { dg-final { scan-assembler-times
"\\t(add|addi|bseti|li|pack|ret|sh1add|sh2add|sh3add|slli|srli|xori|or)" 60 } }
*/
+
+unsigned long foo_0xcafe605f35019fa0(void) { return 0xcafe605f35019fa0UL; }
+unsigned long foo_0x87a80d217857f2de(void) { return 0x87a80d217857f2deUL; }
+unsigned long foo_0x6699f19c19660e63(void) { return 0xe699f19c19660e63UL; }
+unsigned long foo_0xec80e48a137f1b75(void) { return 0xec80e48a137f1b75UL; }
+unsigned long foo_0xc7d7193e3828e6c1(void) { return 0xc7d7193e3828e6c1UL; }
+unsigned long foo_0xfc627816039d87e9(void) { return 0xfc627816039d87e9UL; }
+unsigned long foo_0xbd69e83e429617c1(void) { return 0xbd69e83e429617c1UL; }
+unsigned long foo_0xdbee7ee624118119(void) { return 0xdbee7ee624118119UL; }
+unsigned long foo_0xf3fe20820c01df7d(void) { return 0xf3fe20820c01df7dUL; }
+unsigned long foo_0x8f1dc29470e23d6b(void) { return 0x8f1dc29470e23d6bUL; }
--
2.42.0
