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--- dev:crosscompiler:backend_arm:register_allocation [2018/12/21 10:44] – [Parameter Passing] ursgraf
+++ dev:crosscompiler:backend_arm:register_allocation [2019/01/24 19:44] – [Locals on the Stack] ursgraf
@@ Line 34: / Line 34: @@
 Parameters are passed in R0..R5 and D1..D6.\\
 In the interface //arm/Registers// you can find the definitions about which registers are used for volatiles and nonvolatiles and which are used for parameter passing. Important: the number of parameter registers must be smaller or equal than the number of volatiles. Due to the interleaving of D and S registers in the extension registers, parameters must be carefully copied into the parameter registers. D1 to D6 hold the parameters regardless of the parameter being of type single or double. To give an example. For method //m1(float a, double b, float c, double d)// the four parameters will be passed as follows:
-^S0^S1^S2^S3^S4^S5^S6^S7^S8^S9^
+|S0|S1|S2|S3|S4|S5|S6|S7|S8|S9|
-^  D0  ^^  D1  ^^  D2  ^^  D3  ^^  D4  ^^
+|  D0  ||  D1  ||  D2  ||  D3  ||  D4  ||
-^  ^^a^ ^  b  ^^c^ ^  d  ^^
+|  ^^a| ^  b  ^^c| ^  d  ^^
 ===== Locals on the Stack =====
@@ Line 57: / Line 57: @@
+When dividing numbers of type long, a large number of auxiliary registers are necessary. For these cases the register allocation is run with a reduced register set with the same reserved registers as above given above.

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