https://gcc.gnu.org/g:758d2b3d3e28c831c79f5c18727d149c81896434
commit r15-5440-g758d2b3d3e28c831c79f5c18727d149c81896434
Author: Jakub Jelinek <ja...@redhat.com>
Date: Tue Nov 19 10:25:04 2024 +0100
bitintlower: Handle EXACT_DIV_EXPR like TRUNC_DIV_EXPR in bitint lowering
[PR117571]
r15-4601 added match.pd simplification of some TRUNC_DIV_EXPR expressions
into EXACT_DIV_EXPR, so bitintlower can now encounter even those.
From bitint lowering POV the fact that the division will be exact
doesn't matter, we still need to call at runtime the __divmodbitint4
API and it wouldn't simplify there anything to know it is exact if
we duplicated that, so the following patch lowers EXACT_DIV_EXPR exactly
as TRUNC_DIV_EXPR.
I think we don't need to backport this unless something introduces
EXACT_DIV_EXPR on BITINT_TYPEd expressions on the 14 branch as well.
2024-11-19 Jakub Jelinek <ja...@redhat.com>
PR middle-end/117571
* gimple-lower-bitint.cc (bitint_large_huge::lower_muldiv_stmt,
bitint_large_huge::lower_stmt, stmt_needs_operand_addr,
build_bitint_stmt_ssa_conflicts, gimple_lower_bitint): Handle
EXACT_DIV_EXPR like TRUNC_DIV_EXPR.
* gcc.dg/bitint-114.c: New test.
Diff:
---
gcc/gimple-lower-bitint.cc | 8 ++++++++
gcc/testsuite/gcc.dg/bitint-114.c | 23 +++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 1d1e300643c7..6fc425375b12 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -3597,6 +3597,7 @@ bitint_large_huge::lower_muldiv_stmt (tree obj, gimple
*stmt)
insert_before (g);
break;
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
g = gimple_build_call_internal (IFN_DIVMODBITINT, 8,
lhs, build_int_cst (sitype, prec),
null_pointer_node,
@@ -5560,6 +5561,7 @@ bitint_large_huge::lower_stmt (gimple *stmt)
return;
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
lower_muldiv_stmt (lhs, g);
goto handled;
@@ -5694,6 +5696,7 @@ bitint_large_huge::lower_stmt (gimple *stmt)
return;
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
lower_muldiv_stmt (NULL_TREE, stmt);
return;
@@ -5740,6 +5743,7 @@ stmt_needs_operand_addr (gimple *stmt)
{
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
case FLOAT_EXPR:
return true;
@@ -5931,6 +5935,7 @@ build_bitint_stmt_ssa_conflicts (gimple *stmt, live_track
*live,
{
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
muldiv_p = true;
default:
@@ -6174,6 +6179,7 @@ gimple_lower_bitint (void)
break;
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (s))
{
@@ -6455,6 +6461,7 @@ gimple_lower_bitint (void)
switch (gimple_assign_rhs_code (use_stmt))
{
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
case FLOAT_EXPR:
/* For division, modulo and casts to floating
@@ -6568,6 +6575,7 @@ gimple_lower_bitint (void)
case RSHIFT_EXPR:
case MULT_EXPR:
case TRUNC_DIV_EXPR:
+ case EXACT_DIV_EXPR:
case TRUNC_MOD_EXPR:
case FIX_TRUNC_EXPR:
case REALPART_EXPR:
diff --git a/gcc/testsuite/gcc.dg/bitint-114.c
b/gcc/testsuite/gcc.dg/bitint-114.c
new file mode 100644
index 000000000000..27db4ac28af4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-114.c
@@ -0,0 +1,23 @@
+/* PR middle-end/117571 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 255
+_BitInt(255) b;
+
+_BitInt(255)
+foo ()
+{
+ return (b << 10) / 2;
+}
+#endif
+
+#if __BITINT_MAXWIDTH__ >= 8192
+_BitInt(8192) c;
+
+_BitInt(8192)
+bar ()
+{
+ return (c << 1039) /
0x20000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000wb;
+}
+#endif
