With the recent improvements to the splitting of special cases of
branch patterns on RISC-V, a dependency on an unmerged/in-discussion
change for branch-equals-zero slipped in: this allowed a non-X mode to
be presented to branch-equals-zero (where only X mode is permissible).
This addresses the issue by wrapping the ANYI operand in a paradoxical
SUBREG:X (the high bits can be safely ignored, as we we perform an
and-immediate before the branch in the pattern).
Tested against the GCC testsuite and committed as obvious.
gcc/ChangeLog:
PR target/107786
* config/riscv/riscv.md
(*branch<ANYI:mode>_shiftedarith_equals_zero): Wrap ANYI
in a subreg, as our branch instructions only supports X.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/pr107786-2.c: New test.
* gcc.target/riscv/pr107786.c: New test.
Signed-off-by: Philipp Tomsich <philipp.toms...@vrull.eu>
---
gcc/config/riscv/riscv.md | 8 ++++----
gcc/testsuite/gcc.target/riscv/pr107786-2.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/riscv/pr107786.c | 17 +++++++++++++++++
3 files changed, 38 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/riscv/pr107786-2.c
create mode 100644 gcc/testsuite/gcc.target/riscv/pr107786.c
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index b7bb338ac04..df57e2b0b4a 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -2224,12 +2224,12 @@ (define_insn_and_split
"*branch<ANYI:mode>_shiftedarith_equals_zero"
(const_int 0)])
(label_ref (match_operand 0 "" ""))
(pc)))
- (clobber (match_scratch:ANYI 4 "=&r"))]
- "INTVAL (operands[3]) >= 0 || !partial_subreg_p (operands[2])"
+ (clobber (match_scratch:X 4 "=&r"))]
+ "!SMALL_OPERAND (INTVAL (operands[3]))"
"#"
"&& reload_completed"
- [(set (match_dup 4) (lshiftrt:ANYI (match_dup 2) (match_dup 6)))
- (set (match_dup 4) (and:ANYI (match_dup 4) (match_dup 7)))
+ [(set (match_dup 4) (lshiftrt:X (subreg:X (match_dup 2) 0) (match_dup 6)))
+ (set (match_dup 4) (and:X (match_dup 4) (match_dup 7)))
(set (pc) (if_then_else (match_op_dup 1 [(match_dup 4) (const_int 0)])
(label_ref (match_dup 0)) (pc)))]
{
diff --git a/gcc/testsuite/gcc.target/riscv/pr107786-2.c
b/gcc/testsuite/gcc.target/riscv/pr107786-2.c
new file mode 100644
index 00000000000..ee316a67f87
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr107786-2.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc -mabi=lp64" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-O1" } } */
+
+int c;
+
+int main() {
+ for (;;) {
+ short h = c * 100;
+ if (h & 0x7ff0)
+ break;
+ }
+}
+
+/* { dg-final { scan-assembler-times "andi\t" 1 } } */
+/* { dg-final { scan-assembler-times "srli\t" 1 } } */
+
diff --git a/gcc/testsuite/gcc.target/riscv/pr107786.c
b/gcc/testsuite/gcc.target/riscv/pr107786.c
new file mode 100644
index 00000000000..5246ec7d338
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr107786.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc -mabi=lp64" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-O1" } } */
+
+int c;
+
+int main() {
+ for (;;) {
+ char h = c * 100;
+ if (h)
+ break;
+ }
+}
+
+/* { dg-final { scan-assembler-times "andi\t" 1 } } */
+/* { dg-final { scan-assembler-not "srli\t" } } */
+
--
2.34.1
