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py/compile: Fix edge case when constant-folding negation of integer.
Also adds tests specifically for testing constant folding.
1 parent 2a8d7ee commit 7e12a60

3 files changed

Lines changed: 44 additions & 7 deletions

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‎py/compile.c‎

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -315,7 +315,10 @@ STATIC mp_parse_node_t fold_constants(compiler_t *comp, mp_parse_node_t pn, mp_m
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pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, arg);
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} else if (MP_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[0], MP_TOKEN_OP_MINUS)) {
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// -int
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pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, -arg);
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arg = -arg;
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if (MP_SMALL_INT_FITS(arg)) {
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pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, arg);
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}
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} else {
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assert(MP_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[0], MP_TOKEN_OP_TILDE)); // should be
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// ~int

‎tests/basics/int_constfolding.py‎

Lines changed: 40 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,40 @@
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# tests int constant folding in compiler
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# positive
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print(+1)
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print(+100)
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# negation
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print(-1)
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print(-(-1))
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print(-0x3fffffff) # 32-bit edge case
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print(-0x3fffffffffffffff) # 64-bit edge case
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print(-(-0x3fffffff - 1)) # 32-bit edge case
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print(-(-0x3fffffffffffffff - 1)) # 64-bit edge case
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# 1's complement
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print(~0)
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print(~1)
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print(~-1)
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print(~0x3fffffff) # 32-bit edge case
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print(~0x3fffffffffffffff) # 64-bit edge case
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print(~(-0x3fffffff - 1)) # 32-bit edge case
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print(~(-0x3fffffffffffffff - 1)) # 64-bit edge case
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# addition
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print(1 + 2)
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# subtraction
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print(1 - 2)
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print(2 - 1)
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# multiplication
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print(1 * 2)
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print(123 * 456)
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# floor div and modulo
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print(123 // 7, 123 % 7)
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print(-123 // 7, -123 % 7)
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print(123 // -7, 123 % -7)
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print(-123 // -7, -123 % -7)
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‎tests/basics/int_divmod.py‎

Lines changed: 0 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -6,12 +6,6 @@
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if j != 0:
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print(i, j, i // j, i % j, divmod(i, j))
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# this tests compiler constant folding
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print(123 // 7, 123 % 7)
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print(-123 // 7, -123 % 7)
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print(123 // -7, 123 % -7)
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print(-123 // -7, -123 % -7)
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# this tests bignum modulo
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a = 987654321987987987987987987987
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b = 19

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